Introduction

Efforts to colonize the world after dark (Melbin, 1987) seem to be as old as human history – especially in cities. But the technological means to do so used to be very limited since devices for lighting up the night are crucial for whatever activity is to be pursued at night. During most of human history artificial light for nighttime activities was very dim and extremely expensive. Therefore, only special events or extremely important tasks could be lit. This changed with the invention of gas lighting and especially electric lighting, which made artificial lighting available in ever larger amounts and at shrinking costs.

The triumph of artificial light was also the beginning of the colonization of the urban night. In his seminal study, Murray Melbin (1987) described the mechanisms of this conquest for American cities. Joachim Schlör (1991) analyzed for Paris, Berlin and London how the conquest of the urban night has always been the result of different demands for and implementations of temporal extension: for production purposes, for repair and maintenance, and for the use of that “other space”, that different atmosphere of lighted darkness for amusement and leisure.

With the gradual colonization of the night the topos of the “city that never sleeps” emerged. Its first-time ever use – as far as I could ascertain – was for New York. But meanwhile ever more cities, wanting to be seen as such or even engaging in specific activities to gain this “title”, have been thus described.

Due to the proliferation of ICT, processes of internationalization and globalization in the context of worldwide economic competition have increased and national time regimes have lost part, if not all, of their relevance. Telecommunicative connectivity is hardly concerned with different time zones, connectivity takes place at any time and location, and locations in different time zones become mutually dependent. The most advanced expression of this development is time zone shifts. Several countries have taken internationalization as a rationale for justifying temporal extensions in the production sector. In the period marked by the broader proliferation of these tendencies, several studies were published that described societies on the way to incessance (already Melbin 1987): Moore-Ede (1993) conceived of this development as a tide: “The benefits of our twenty-four-hour society are enormous. This is a tide that cannot be turned” (Moore-Ede, 1993: 66). He argued that given the high economic revenues it seemed important for societies to adapt to and deal with the side effects, and consistently claimed that societies that “know 24/7” (the name of the consultancy he later founded) would have an edge in international competition. But societies had also to develop appropriate techniques and forms of organization to deal with the fact that the “design specs of the human machine“ (Moore-Ede, 1993: 19) are originally not suited to nighttime activities: ”The solutions we must seek require a rethinking of society, and a sophistication in biotechnology to adapt the human body to the technology and the technology to the human body” (Moore-Ede, 1993: 8). Americans, he argued, had an advantage in this respect because of their openness and flexibility. Kreitzman (1999) also described the problems of the 24 hour society but nevertheless praised it enthusiastically: “The 24 Hour Society means completely rethinking how we observe and use time, breaking away from the traditional constraints of night and day, week and weekend. People are going to have to rework their sleeping patterns, perhaps even their internal body-clocks, to cope with a world that is always open” (Kreitzman, 1999: blurb). „The old time markers of night and day, morning, noon and night, weekday and weekend, are losing their relevance“ (Kreitzman, 1999, https://www.timeshighereducation.co.uk/books/surviving-in-the-world-that-never-sleeps/158035.article). A study conducted at the German Institute of Urban Affairs analyzed the temporal extension in cities in the German-speaking world. The title indeed questions whether it is really necessary for everything to be offered at any time, but the authors conclude that the tendency towards temporal extension is obvious (Eberling and Henckel, 2002).

Many of these texts have in common that they contribute to the proliferation of the 24/7 topos and describe it as a general tendency. There is considerable evidence that a general temporal extension as well as the debate on 24/7 and the notion that we are living in a society that has lost its rhythms has become rather commonplace by now: “Meanwhile we have changes towards a non-stop 24-hour society which sweeps away the natural rhythms of day and night, of weekday and weekend, of summer and winter” (Sträter, 2015: 3, my translation); or: “A growing percentage of social and economic life now takes place in the hours after dark. Currently developments towards 24h cities tend to blur our perception of day and night” (ARUP, 2015: 13).

Only recently, new texts have been published which support the thesis of a tendency towards a 24/7 society (Hassan and Purser 2007; Crary, 2013) or focus on the further colonization of the night and the development of the nighttime economy (e.g. Gwiazdzinski, 2005; Roberts and Eldridge, 2009; Sandhu, 2010; Urban Studies, 2015). In 2014, a night manifesto was published in Sao Paolo, which has meanwhile been presented in several cities worldwide. This manifesto describes nightlife as a new frontier for an old society, and consequently its main claim is that there is a right to the urban night and that citizens are entitled to a fully-fledged 24-hour city (Collaboratorio, 2014).

At the same time there are quite a number of indications that call into question the extent of the existing, or wished for, temporal extension and raise doubts as to the general tendency towards incessance. This feeds the suspicion that “24/7” and the “round-the-clock society or city” are nothing but marketing terms designed to induce a change of perspective (perspectivation), if not slogans or battle cries aiming to assert a prerogative of interpretation (“Deutungshoheit”). Therefore, the time seems right to check the reality of the 24/7 city and, especially, analyze the facts which contradict the claim that there is a general temporal extension and development towards 24/7.

Research Questions, Methods, Structure of the Text

Evidence for temporal extension – as indicated in the introduction – will play a role throughout the text. Actually, however, my aim is to check how far the claim that societies and cities have developed and keep developing towards 24/7 (understood to be more than nightlife in terms of entertainment) will stand up to critical appraisal. Therefore, I will primarily look for evidence that contradicts the general tendency towards 24/7.

Empirical evidence that would allow for a comprehensive description and analysis of the urban night is rather scarce and in no way systematic. Empirical knowledge about the night and the day-night relation is insufficient – there is a great need for research in this field. In this contribution I will propose some theoretical considerations and collect and analyze a variety of empirical data from different fields, relating to the question of the temporal extension of urban activities towards 24/7. I will, therefore, present both evidence that supports the claim that daytime and nighttime levels of activity tend to level out, and evidence that calls this claim into question. The contribution is based on a review of the relevant literature, selective statistics, empirical studies and the findings of my own research as well as on expert interviews. In this, my special emphasis will be on cities – such as New York, London, Shanghai, and Berlin – with an image of having high temporally extended activity levels. I will use indicators and evidence from various fields such as night work, shop opening hours, service times, online usage, nighttime public transport, sleeping times, artificial light at night.

In the first chapter, I will discuss the concepts of extension, colonization of the night, nighttime economy as well as the notion of 24/7 and how it might be systematized. I will then describe such facts and factors as suggest the prevalence of a much more traditional day-and-night rhythm in cities – even big cities. Finally, the findings will be contrasted with the claim for 24/7. If the facts contradict the notion of 24/7, the question to deal with will be why this notion of “24/7” has become so widely diffused. Moreover, policies of dealing with the night will have to be questioned. Some conclusions will be drawn, and directions for further research will be suggested.

Notions and Concepts

Even if the notion of 24/7 – as in “24/7 city” or “24/7 society” – is widely diffused, its exact meaning remains rather unclear. Therefore, there is a certain need to clarify what it could mean in general and what it will mean in this article.

The colonization of the night can be interpreted as one of the many decouplings from natural rhythms that mark the history of mankind. At all times, and depending on a variety of objectives, technologies have been developed to accelerate, decelerate, or reshape otherwise natural rhythms. With the invention of artificial light the reshaping of the day-night rhythm started its as yet unfinished triumph. The wider diffusion of artificial light triggered the extension of activities into the night on a broader scale and initiated the colonization of the world after dark (Melbin, 1987). Besides entertainment, the provision of infrastructure and the maintenance of security and order played a major role. Night guards and lamplighters were the first to work at night, followed by policemen, health and emergency services, fire brigades, public utilities etc. The use of the night for entertainment and leisure followed suit. Production activities, in contrast, were less quick to extend into the night because of the need to have the workforce travel to and from the workplace.

By and by – depending on economic and technical developments – ever more functions were extended, or even transformed to offer 24/7 service. An interesting example is television. In Germany even in the late 1960s and early 1970s the (then three) TV programs regularly closed down at midnight with the national anthem or the test pattern. This did not change until the onset of privatization (1984 the first private TV station started operations in Germany), on the one hand, and increasing global networking, on the other; meanwhile, hundreds of stations and programs are round-the-clock available (to say nothing of streaming, download and archival features).

Internationalization (increase of worldwide competition, i.e. competition also with respect to allowed times) and the growing capital intensity of many lines of production (exerting pressure on amortization times) have served as another push towards temporal extension. European and international integration has been accompanied by a general deregulation. Restrictive temporal regulations have been relaxed or abolished (e.g. shop opening hours in Germany, pub opening hours in GB, service times in many countries).

Further pressure on supply times, especially for services, has come from temporal shifts in demand due to changing working hours and the increase of female labor market participation. Examples are doctors, gyms, public services, and even childcare services. These changes have also pushed the demand for nighttime public transport. Therefore, the development of public nighttime transport networks is a very informative indicator of the general tendencies towards temporal extension in cities (cf. Patermann, 2012, for Berlin; Magnan and Suetova, 2012, for a Paris-Berlin-London comparison).

While these descriptions indicate some causes of temporal extension, there is no clear-cut definition of what “night” actually is and what, as a consequence, has to be seen as an extension. What is meant by 24/7, is even less clear. In the EU statistical definition of nighttime work, “night” is the time from 11 pm to 6 am. But in collective wage agreements (regarding night surcharges) other definitions are rather common; in local regulations and bylaws night is defined by acceptable times for noise, in urban lighting regulations by the 100-lux line (less than 100 lux is night). In everyday language, night is when it is dark, but the length of the night still varies with the seasons and the latitudes.

The distinction between urban night and nighttime economy has become even less clear because in recent years – and especially in the Anglo-Saxon world – research and urban planning have increasingly focused on nighttime economy. This type of analyses, however, is only concerned with nighttime entertainment, nighttime leisure, and nightlife (Lovatt et al., 1994; Roberts and Eldridge, 2009; Urban Studies, 2015). The following definition is revealing in this respect: “The term NTE (night time economy, DH) now tends to refer to the assemblage of bars, clubs, cinemas, theatres and cultural festivals and events at night time which are, in a context of urban entrepreneurialism, supposed to contribute to urban regeneration and local economic growth” (Van Liempt et al., 2015: 412). Considering the little knowledge we have about the small hours of the night, Hadfield (2015) ironically states: “The late-night economy period, from midnight to 5:00 h may be different culturally and in terms of implementation, from the hours of 18:00-23:59, but we know much less about the former, as all but the most committed ethnographers have retired to their beds” (Hadfield, 2015: 613f).

With respect to the notion of 24/7, I feel that this restricted conception of nightlife is a much too narrow focus. Nighttime economy in the restricted definition only accounts for a certain part of urban nighttime activities, albeit an important one. Kreitzman (1999) already insisted on a broader perspective (drawing, however, on euphoric ideas of the 24/7 society). “The 24 Hour Society is mainly regarded in terms of shop opening hours. But it is far more than that. Eventually, it will lead to a different construction of daily activities, freeing people from the restraints and deadlines imposed at present by the rigid adherence to the clock. We will break away from the thinking that there are a fixed number of hours per day for selected activities and move into a more flexible and free-wheeling approach, co-ordinating activities on the fly“ (Kreitzman, 1999: 156). A more comprehensive analysis would need to start out from a much more intricate relation between urban day and urban night in order to find out whether there is indeed an extensive and complete adaption to and alignment of urban daytime and nighttime activities.

Regarding 24/7, there are rather pronounced statements, e.g. by Mitchell (1995) or, more recently, by Crary (2012), e.g.:

• “Just as each city has its characteristic spatial organization, so it has its own daily, weekly, and seasonal rhythms – very different for New York, Delhi, and Tokyo. As there is prime real estate, so there is prime time. But now extrapolate to an entirely asynchronous city: Temporal rhythm turns to white noise” (Mitchell, 1995: 16).
• “24/7 announces a time without time, a time extracted from any material or identifiable demarcations, a time without sequence or recurrence. In its reductiveness, it celebrates a hallucination of presence, of an unalterable permanence composed of incessant, frictionless operations” (Crary, 2012: 29).
• “Thus urban nights are getting more similar to urban days and Sundays capture some of the properties of week days. Continuity is thus not only a purely quantitative phenomenon assessed by a general increase of activities: the daytime and nocturnal landscapes of stores and services are undergoing a significant transformation and more and more tend to resemble that of other urban times” (Mallet, 2014: 11).
• “Powerful social trends and global economic forces continue to drive the 24-hour city throughout the modern world” (Furedi, 2015: 6).

Beyond these rather alarmist quotations, more substantial statements are hard to find. My search for precise demarcations or even operationalizations of thresholds beyond which a city might be called 24/7 resulted in the following findings:

• For specific functions, this threshold is easy to define since the point, then, is only the 24 hour service; but what about spaces?
• Beyond which threshold can one speak of a leveling of the differences between day and night, and beyond which temporal extension concerning how many functions a location or space might be defined as incessant?
• Which threshold of leveling between day and night is required for cities or quarters to be defined as 24/7?

Strictly speaking, a definition of 24/7 would have to include thresholds of leveling between day and night that are based on specific indicators, on the one hand, and to factor in the relevance of these indicators for urban (public) spaces, on the other, since automatized functions do not seem relevant in this context. Cities may well become 24/7 in a virtual sense because given the proliferation of many types of surveillance (especially in the context of smart city development) ever more control functions that operate round the clock (and produce data that may even be relevant for urban studies) are being implemented. But this does not mean that cities as social entities in public space are getting more temporally extended. For that to be the case, extended activities would have to be a distinctive feature of the public space in question.

Therefore, a distinction between 24/7 societyand 24/7 cityseems appropriate. Net-based provision of 24/7 functions is ever more expanding. But much of the functions that are transferred (or transferable) into the night, such as information, TV, entertainment, games but also online shopping or banking and even work, take place in private spaces with practically no impact on public urban spaces. The very question whether orders placed – and automatically processed – during the night are also commissioned or even delivered during the night raises many doubts. To put it more generally: Many 24/7 services are automatized, and orders are processed automatically, but the materially relevant tasks are carried out during the day. Many call centers operate during the night and thus contribute to 24/7 activities but have little impact on the city, especially if they are located in other time zones (or in the periphery of the agglomeration or even the country) to economize on labor costs (low wage countries or avoidance of night surcharges). The virtual 24/7 society may also be growing through new forms of a worldwide division of labor, an extreme form being time zone shifts. Journalism is an example: Journalists for European online journals or newspapers work e.g. in the USA to contribute to the continuous update of news, and publishers thus avoid the costly night surcharges.

Even urban planning documents that deal more intensively with extended activities or even propagate 24/7 do not say anything about what 24/7 could mean. In their majority they focus on nightlife (nighttime economy in the narrower sense) and its enhancement and regulation, and on how to solve the resulting conflicts. But they do not deal with the urban night in a broader sense (stadtnachacht, 2015). Since nightlife is a relevant economic factor for many cities, there are implicit preferences for nighttime economy (Vogelpohl, 2011). This leads to the conclusion that concepts for extending nighttime activities, the urban night or even the 24/7 city are primarily marketing concepts designed to lay claim to a position in the international competition of cities, or are planning goals for the revitalization of inner cities which have lost their functional diversity (e.g. the English and Australian initiatives, stadtnachacht 2015 etc.).

Thus the 24/7 city and society seem to be fuzzy concepts in the sense described by Ann Markusen (1999): Everybody can talk about them – which is part of their fascination and contributes to their proliferation – but you never know whether everybody is really talking about the same thing. Even Kreitzman wrote that “… the 24 hour city is more a collection of ideas and methods than a literal description” (Kreitzman, 1999: 137). For 24/7 to become a valid concept, a definition of a threshold or a range of leveling between day and night is necessary. For the 24/7 society, the decisive question is how many people are active in economically relevant terms during the night. For the 24/7 city(or parts of it), the decisive question is the degree of leveling between daytime and nighttime activities in public space.

Empirical evidence

In the following paragraphs I will present eclectic empirical results to check whether a general tendency towards a continuously active society and especially a24/7 city can be detected. This is done for the following fields:

• Extended work, nighttime work, weekend work
• Opening hours of shops and selected services
• Online uses such as shopping, call centers, internet use
• Nighttime production and productivity
• Nighttime public transport
• Sleeping times
• Artificial light at night and activities
• Types of cities and parts of cities

Extended Work

Statistically, nighttime work is defined as work that is done between 11 pm and 6 am and lasts for at least two hours. If (western) societies were directly heading towards 24/7, one would therefore expect to see relevant statistical increases in evening, nighttime and Sunday work. The available data are not very useful in this respect since they are based on different concepts and, in most cases, not broken down to different sectors, functions, and especially spaces. I have not found any data for cities in comparison to other spatial entities, let alone for specific cities or parts of cities (quarters). But even if we allow for these shortcomings, the available data is not very conclusive in terms of a massive tendency towards 24/7 (particularly because many extended functions are located in rural areas since agriculture is a temporally rather extended sector).

Evening Work

Working time extensions beyond the edges of the normal working day (primarily evening work) show the greatest increase. Furthermore, the respective data attest to an increase in the polarization of working hours (extensions or stable levels for highly qualified personnel and freelancers, and reductions for the less qualified), in working time flexibility, standby service, and shift work (excluding nighttime work).

German statistics provide a rather instructive example in this respect: The share of employees working in the evening (6 pm till 11 pm) rose from 15 per cent in 1994 to 26 per cent in 2014 (for freelancers with employees the share is even 45 per cent) (Statistisches Bundesamt, 2015).

Nighttime Work

In absolute terms, an increase in the number of nighttime workers is more than probable. One reason is the growth of infrastructures that operate or have to be monitored 24/7 (e.g. airports, ports, power stations). Another growing group is professions characterized by a constant change of time zones – pilots, flight attendants, messengers, some types of managers, actors, musicians etc. Finally, the massive industrialization of the global south plays a major role since certain industries (chemicals, steel production, and the like) have always been 24/7 functions. Additionally, industries which profit from less strict regulations due to international competition may have extended their night time workforces. In terms of spatial impact, the decisive factor is where these types of industries are located and where the workers live.

Selective sources indicate rather high percentages of nighttime work in different countries, as illustrated by the following figures: “18% of China’s, 19% of the UK’s and 27% of the United States‘ working population are performing some kind of night work during the hours from 10 pm to 6 am“ (ARUP, 2015: 19). But the data is imprecise and, due to insufficient sources, cannot be checked.

EU statistics show quite remarkable differences between countries and sectors, but the overall increase of regular nighttime work[1] is not very remarkable (see table 1). In 2014, only two countries (Malta and Slovakia) have a more than 10 per cent share of nighttime workers, and the only other country which in former years had a more than 10 per cent share (the UK) has experienced a remarkable reduction. Even the share of people who work at night only occasionally has not notably increased (6.8 per cent in 2014 for EU 28).

Table 1: Employed Persons Working at Night regularly (occasionally), as a Percentage of the Total Employment

EU	1995	2000	2005	2010	2011	2012	2013	2014
EU 15	5.6   (9.7)	8.4   (2001: 9.1 (u))	8.4 (bu)   (7.6 (bu))	8.0   (6.8)	8.0   (6.8)	7.0   (7.2)	6.4   (6.9)	6.4   (6.8)
EU 28			7.9 (bu)   (8.5 bu))	7.4   (7.6)	7.4   (7.6)	6.6   (8.0)	6.2   (7.8)	6.1   (7.8)
Euro Area 19			7.9 (bu)   (7.3 (bu))	7.6   (6.6)	7.5   (6.7)	7.4   (6.7)	6.8   (6.2)	6.8   (6.1)

b – break in time series, u – low reliability

Source: Eurostat 2015, my compilation.

A range of more specific data and surveys produce different numbers for different countries. For Germany, a rather compact summary of various statistics – sometimes using slightly different operationalizations – concerning the development of nighttime work over the years reveals that the fraction has never exceeded 14 per cent and has been clearly less than 10 per cent in recent years (2013). Due to different concepts, the data is not rigorously comparable but still suggests that overall nighttime work did not change that much.

More recent research for Germany shows that with respect to qualification, nighttime work is more prevalent among the less qualified, and with respect to age more prevalent among the younger age groups. To a relevant part, nighttime work (as my own case studies also indicate) is a transient phenomenon for younger people as part of their training, or for those who like to profit from the extra pay and still have the power, or a phenomenon for people with little choice (there also is a very small group who do nighttime work on a voluntary basis for longer periods). This structure suggests that nighttime work does not gain in attractiveness and that compensation has to be high enough to provide incentives also for those with a higher level of qualification. It shows moreover that the pressure is not (yet?) strong enough to make nighttime work a mass phenomenon without compensation. With rising levels of qualification, it might even become more difficult. The end of sleep as insinuated by Crary (2013) in the subtitle of his book is, in my view, an unwarranted conclusion.

For most of the countries, structural change in the economy of course plays a major role – also regarding the future: Nighttime work is in decline in manufacturing (i.e. due to automation and the relocation of certain industries to other countries) and on the rise in the services. This rather more visible development is a result of, among other reasons, rising incomes, the extension of leisure times and entertainment, the rise of transnational collaboration, higher capital intensity also in the service sector (e.g. CRT in medicine) and the resulting amortization pressure. Therefore, and due to rising conflicts as a result of the extension of entertainment, on the one hand, and of the fact that social groups for whom this previously was very exceptional are getting into night work, on the other, the debate on 24/7 is drawing much attention.

To sum up: The developed world is undergoing a structural change from manufacturing to services, but the data show that in the net effect, the share of nighttime work has not only not increased but has actually declined (at least in relative terms) in many European countries in recent years. This is also a key statement of the Forth European Working Conditions Survey (European Foundation, 2007: 20): “In terms of EU workers with schedules outside the ‘normal’ working day, the results do not point to an increasing diversification of working hours, or a trend towards a 24-hour society. If anything, the proportion of people working outside normal working hours has slightly decreased since 1995”[2].

Weekend Work

In EU25, work on Saturdays is most prevalent in Southern Europe, while Sunday work is most often found in the Netherlands and in Scandinavia (European Foundation, 2007: 20).

Weekend work occurs mainly in agriculture and in hotels and restaurants (European Foundation, 2007: 21).

Germany has seen a significant increase in weekend work between 1994 and 2014 – from 21 per cent to 26 per cent for Saturdays, and from 10 per cent to 14 per cent for Sunday work (defined as permanent work on – every – Saturday/Sunday, or otherwise regularly) (Statistisches Bundesamt, 2015). According to one survey, the share of those who sometimes work on Saturdays and/or Sundays is even 66 per cent (BIBB and BAuA, 2012). This is probably a result of less restrictive regulations, especially regarding shop opening hours.

Development of Operating Hours of Shops and Selected Services

Operating hours of shops and services have been extended during the last decades – probably all over the world – but surely in Germany. Operating hours of public and private services are closely related to the type and extent of regulations, which varies considerably between countries, states and sometimes even cities. In many countries there has been a massive deregulation of temporal arrangements.

A very revealing example is the extension of shop opening hours in Germany, where rather restrictive regulations were in place till the 1990s. Meanwhile the regulating power was devolved to the states (Länder). Especially in many big cities, supermarkets with substantially extended opening hours have evolved. Only recently a supermarket chain in Berlin advertised opening hours of 24 hours – from Monday 6 am till Saturday 12 pm – for at least some of its stores; Sundays, however, remain closed in this case[3].

With the deregulation of shop closing hours, Sunday opening hours have also extended despite the fact that Sundays are still rather strictly regulated. But even before that, bypass rulings and exemptions existed – e.g. for stores at traffic nodes (main train stations, airports). By bypassing shop closing regulations, gas stations have changed into 24/7 locations with convenience stores, generating more profit from sales from the store than from the sale of gas (Rieder, 2000).

Practically no extension took place for pharmacies in Germany. For decades, pharmacies have had a rather sophisticated kind of shift system for 24/7 emergency services. Quite a few extensions have been implemented for doctors (into the evening) and gyms (into the evening and sometimes even 24/7).

Even public services have been subject to extensions. In the early 1990s, a Thursday “service day” was introduced for the first time, with public services operating till 8 pm. This was later extended to other days, and service hours were introduced even for Saturdays. But – with the exception of online services – temporal extensions are mainly limited to the early evening.

As a rather special case, the availability of nighttime kindergartens would provide strong evidence for a leveling of urban daytime and nighttime rhythms. Rather spectacular reports on nighttime kindergartens every now and then surface in the German media. But there is practically no comprehensive empirical study of the phenomenon. The journal of the German Society for Time Policy (Deutsche Gesellschaft für Zeitpolitk), Zeitpolitisches Magazin (2013) has been the only one to give an overview on the situation in Germany and Berlin. Despite expectations that nighttime kindergartens would spread, no relevant degree of nighttime child care has been observed[4]: “Rather quickly, it turned out that fears of a major spread of nighttime kindergartens due to the implementation of flextime arrangements were unwarranted; as far as we can see, these establishments are not successful because there are not enough parents ready to enroll their children in them” (Zeiher, 2013, my translation). There are two dimensions to this: parents do not want their children to attend these kinds of establishments, on the one hand, and those parents who would be most in need of nighttime child care cannot afford it, on the other. Quite recently, however the number of nighttime childcare facilities seems to be on the rise in some countries. In summer 2015, the German Federal Government started an initiative to provide evening, nighttime and 24-hour childcare services and will fund it with 100 mill. Euro (e.g. http://www.sueddeutsche.de/politik/kinderbetreuung-ministerin-schwesig-plant-stunden-kitas-1.2551083).

In sum, there is a rather pronounced temporal extension of services, but they are rather selective in terms of space and function and – except for traffic nodes, gas stations, several big cities and extremely specialized tourist destinations – do not regularly operate past midnight.

Online Services and Uses

Online Shopping. Online shopping has been growing for years, partly complementing and replacing stationary shopping. Since online shopping is round-the-clock accessible, the temporal distribution of orders provides a clue to shoppers’ activity times – even if orders are placed from indoor locations. It seems plausible to assume that commissioning and delivery do not take place during the night.[5] Therefore the empirical evidence rather suggests traditional rhythms.

A study by WorldPay (2012) reveals a peak of orders in the evening hours. 74 per cent of them are placed between 12 am and 12 pm, with a worldwide average peak at 8.40 pm (WorldPay, 2012: 8). This indicates an extension into the evening and early night, but given that only 10 per cent of the orders are placed between 12 pm and 6 am it cannot be taken as evidence for a leveling between day and night (WorldPay, 2012: 8). Online shopping offers more temporal flexibility, but most of the orders in Germany are placed during regular shop opening hours (Stepper, 2015: 168).

Call Centers. A specific sector with a high affinity to temporal extension is call centers. In many cases the explicit goal is a 24/7 on-call service. The number and importance of call centers has grown significantly in the last decades – especially due to the availability of supporting technologies, falling telecommunication prices, fiercer competition regarding service quality and client orientation, and strategies by enterprises to cut costs through outsourcing (even abroad), which has allowed them to enhance their services and, more specifically, their service times. Yet call centers are a function that has practically no impact on public space because services are demanded and delivered within buildings that – despite employees’ commuter traffic – do not generate activity in public space. Empirical studies, however, are very hard to find.

The answer to a parliamentary question for one state in Germany (Sachsen-Anhalt) shows that more than 70 per cent of call center employees work between 6 am and 10 pm (Landtag von Sachsen-Anhalt, 2013: 6). The sketchy evidence shows above-average temporal extension as compared to the rest of the economy and a higher proportion of nighttime work. But it is a very small sector, and still a far cry from any close-to-equal distribution between day and night.

Online Uses. Tablets, Smartphone, Servers. Most types of online connection use have a very limited impact on public spaces in terms of visible activity, but they might at least indicate a general tendency towards temporal extension.

An international comparison shows remarkable differences in the temporal patterns of internet use. AT-Internet published a study on the preferred surfing times of internet users in ten European countries. Between June 1 and June 30, 2009, the use of 14,825 websites was analyzed. More than double the number of Portuguese than Germans are surfing late at night. Country-specific habits – like the Spanish siesta – are clearly reflected in the use pattern. Sweden and Switzerland have much more visits, on average, at 7 am than the other countries. Portugal, Spain and Norway, on the other hand, have higher shares of visits between midnight and 1 am than any other country (news.worldsites-schweiz, 2009) (see chart 1). This might be a result of traditional differences in daily rhythms in different countries and cultures: The southern, and warmer, European countries typically have extended rests at noon and more activities later in the evening (even for meals). But essentially this still suggests that in the small hours of the day, user numbers are also small.

Between 2010 and 2015, mobile internet use via smartphones has increased by 175 per cent to 76.5 per cent of all users (Tomorrow Focus Media, 2015: 10). But this survey also shows that use in the small hours is rather low while the peak corresponds to the peak commuting time in the early evening (Tomorrow Focus Media, 2015: 14). Over 76 per cent of users use their smartphones mainly for private purposes (Tomorrow Focus Media, 2015: 17). Tablet use is even more concentrated on private homes, with peaks in the evening between 5 and 11 pm and little use (less than 5 per cent of users) in the small hours between 1 am and 6 am (Tomorrow Focus Media, 2015: 10).

Even a very specific analysis of tablet usage indicates rather traditional rhythms. Regarding private use there is a peak between 6 pm and 11 pm which is higher on weekdays than on weekends. But, most importantly, only less than 10 per cent of users are online after 11 pm (BVDW et al., 2014: 10)(see chart 2).

Even the use of smartphones is subject to a clear day-night rhythmicity, as shown by a study in England (Ofcom, 2014). Accordingly, due to the smaller number of users, the download speed is higher during the small hours (Ofcom, 2011: 30).

With regard to the utilization rate of servers – irrespective of spatial implications – one would expect to find a distinct tendency towards 24/7 in this highly automated and globally integrated field. For 2012, and owing to an illegal botnet established by hackers, internet activities could be shown on a worldwide basis (Carna Botnet, 2012). By combining the activity level with an underlying animation layer attuned to the day-night cycle, the botnet revealed that even the temporal patterns of use for this technology follow a rather classical rhythm, i.e. activity levels drop sharply during the night all over the world (see chart 3).

Development of Night Time Traffic

Due to the development and extension of nighttime public transport networks – nighttime traffic for public transport is defined as passenger traffic during the night and early morning, mostly concentrated on weekends – nights could be interpreted as a rather clear indicator of general tendencies towards temporal extension in a city. In several European metropolises nighttime transport networks have been developed and extended since the early 20th century (well documented for Berlin in Patermann, 2012). Only the extension of the net can serve as an indicator in this context because the maintenance of nighttime traffic is relatively costly. (Unfortunately, no systematic studies on its use and potential change could be found.)

An international comparison of selected big cities with an image of being temporally much extended reveals remarkable differences, especially for railbound traffic. Railbound public transport that operates all night (like in New York or Berlin on weekends) is a great exception. London will start a restricted nighttime tube service by September 2015. Also Shanghai – which in the Western perception is a temporally rather extended city – has no relevant nighttime public transport network, and the underground has very limited operating times, i.e. from 5.30 am till 11 pm, at the latest. Normally, the frequency of service is much lower during the night. At night, most of the cities with an extended railbound public transport network switch to a night bus network because of the lower costs. This is true also for metropolises such as Paris and London⁷. (http://en.parisinfo.com/discovering-paris/themed-guides/paris-by-night/practical-guide/night-transport-in-paris; http://www.visitlondon.com/traveller-information/getting-around-london/london-bus). Only in very few big German cities (Berlin and Hamburg), nighttime traffic has been rather common for quite a time. In other German cities, development of nighttime public transport networks started as recently as in the late 1980s-early 1990s).

The development of a nighttime network depends on the general policy of the cities’ governments, the relative importance of different modes of transport, and the importance placed on the night. A relatively drastic example of the neglect of nighttime public transport can be studied in Milan (ISR 2013) and the Po valley (Stablini and Zedda, 2011). Major parts of Milan are not accessible by public transport during the night (see chart 4); nighttime coverage of stations in Milan is 15 per cent in comparison to 47 per cent in Berlin (ISR, 2013). If in the small hours you want to get to a specific location and have no car at your disposal, the routes planning system of the public transport provider in Milan recommends taking long walks.

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Even worse, the whole Po valley is very poorly accessible during the night by public rail transport (Stabilini and Zedda, 2011). For major parts of the territory, no accessibility is provided at all, the private automobile being the only alternative during the small hours (see chart 5). This may not be specific for all of (Northern) Italy, but in many parts of the world it is a rather common phenomenon. However, I do not know of many studies in this respect, let alone a systematic comparison.

Public nighttime traffic obviously exists only in a rather small number of big cities, and even cities where one would expect to see an elaborated system offer a rather limited service. For most of the cities a very pronounced difference between day and night still prevails, even if some extensions are noticeable. The eclectic evidence shows that despite the noticeable extension of nighttime public transport nets, the latter are mostly limited to (very) big cities, and services lag way behind what one would expect in terms of a relevant leveling of day and night activities. Undoubtedly a comprehensive comparison of nighttime public transport networks in a relevant number of cities would be a valuable research endeavor.

Sleeping Times

A much-discussed indicator that also reflects culturally different behaviors is the average duration  (and distribution) of sleeping times. It has by now become a commonplace to say that during the last century or so, and due to the temporal extension of activities in the western world, sleeping times have been remarkably reduced (and the times of turning in postponed): “Among individuals in industrialized societies, average sleep duration has decreased from about 9 hours per night in 1910 to about 7.5 hours presently” (Takar and Hirshkowitz, 2003: 47, no reference provided, as for most statements of this kind). Reliable statistics on sleeping times 100 years ago do not exist. In a recent study exploring whether sleeping times could be used as a backing for Rosa’s (2005) acceleration theory, Hsu (2014) comes to the conclusion that evidence on sleeping times is very inconclusive and, therefore, does not support Rosa’s claims. “We should be wary then of claims which posit that there has been a long-term linear decline in the average amount of time being devoted to sleep in the Western world, for there is not enough scientific evidence to establish if this has wholly been the case” (Hsu, 2014: 220). This skepticism is backed by other publications (Quartz 2015, National Sleep Foundation 2013). Based on some more recent surveys, Roenneberg (2013) concludes: “Our results suggest that although people sleep for the same amount of time on work-free days as they did ten years ago, on work days, they sleep for about 38 minutes less than they used to” (Roenneberg, 2013: 428). Selective data collection and the differences between self-reported sleeping times and measured sleeping times are major problems in this context.

A survey conducted by the German statistical office between April 2001 and March 2002 (12,600 participants) reveals that the average sleeping time is 505 minutes, i.e. 8.4 hours, and that even for the age bracket of 30-44, which gets the least sleep, it is still 482 minutes, i.e. 8.0 hours (Statista, 2015). These results, too – even though I am highly skeptical regarding the design of the study – do not indicate a relevant reduction of sleeping times.

Smartbands are a new technique to survey individual body functions and activities according to certain criteria (walking distances, sleeping times, eating times etc.). By compiling these data, statistical analyses – e.g. by location (see chart 6) – become possible (Roenneberg, 2013). An analysis of several thousand users of the Jawbone smartband allows for a differentiated overview of sleeping times in several cities: “Here are the sleep patterns of UP wearers for seven cities from Monday, March 31, 2014, a typical night. New Yorkers work hard and play hard, and they’re the first to bed and among the first to rise. Users in Tokyo are among some of the last to go to bed and the first to wake up, since they only average 5 hours and 46 min of night sleep. Dubai has the most leisurely sleep schedule, with 10% of users still asleep by 11am. In Beijing, you can see workers taking their afternoon workplace naps. We can also see people in Madrid taking their afternoon sleep (although it’s much more common on weekends, with greater than 10% of UP wearers logging a siesta). Only a maximum of 95% of a city is asleep at any given time, since the early risers are awake before the last to sleep are in bed” (Jawbone 2014). Inversely, one can say that as long as there are times when 95 per cent of the population sleep, the evidence for 24/7 and a leveling of day and night is rather weak.

Even if we bear in mind that the data is not representative – the number of participants is not high enough to be representative in all cities, and users are characterized by relatively high incomes and a high affinity to new technology, which may also imply extended life styles – the sleeping patterns are rather traditional. Even with high degrees of freedom, a general tendency towards round-the-clock activity can hardly be deduced if at least 80 per cent of the population indeed sleep at the times one would expect diurnal primates to do just this.

Even this small empirical evidence shows the importance, and probably also path dependence, of the specific characteristics and cultural peculiarities of different countries (southern cultures are later than northern ones[7]). Alignments are probable but a homogenization between day and night is hardly visible.

Artificial Light at Night and Activity

The regimes of nighttime artificial lighting in different cities – which are also path-dependent and related to different cultural practices – could provide at least some indications of temporal extension since artificial light is a prerequisite of nocturnal activity. Everybody knows the pictures taken from the ISS, or of the nighttime skylines of very brightly lit cities – e.g. Shanghai. The satellite images give the impression that this is thestatus of nighttime illumination as visible from space. That this is not true can be proved by time lapses. By producing time lapses at different locations in Berlin (https://vimeo.com/channels/citynightlapse or https://www.youtube.com/channel/UCh4VXgoLvFHgLN6mGMY2gAg) (similar productions are under way also for other cities) we could show that illumination is not only changing quite remarkably in the course of the night, but also in quite different ways and intensities at different locations. Looking for nighttime activity at Alexanderplatz, Hackescher Markt und Potsdamer Platz (shopping, gastronomy, leisure, public transport), we were able to recognize 24/7 activity only to a very limited extent (Meier, 2016 in preparation).

Thus even in cities with an image of being temporally especially extended, the temporal extension of artificial light we can actually see is surprisingly small. Shanghai is a very remarkable example in this respect: In this city which gives the impression – in satellite images and images of the skyline – of being especially brightly lit, nearly every light source in public space except street lighting (billboards, screens, building illumination, shop illumination) is switched off at 10 pm or 11 pm – the very time that marks the beginning of nighttime work according to the international statistical definition. (As mentioned above, this is also related to the very restricted operating time of public transport.)[8]The city, then, gets really dark (see charts 7).

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The relation between artificial light at night and the level of nighttime activities is all but clear. The levels and patterns of activity depend on the range of options, the functional diversity, the lighting intensity, the lighting techniques (and even regimes) that even on a small scale are rather differentiated and socially and technologically path-dependent (Meier, 2016). Besides the lighting regime, surveillance strategies also play an important role. “Where and when light should be switched off or reduced is a political question since it requires the establishment of profiles of nocturnal use. … Whoever successfully designs the nocturnal image of the city also has a relevant control over different use patterns in public spaces” (Schulte-Römer, 2013: 32, my translation).

Spatial Relevance of 24/7 – Types of Subspaces and Cities

I have already touched on the necessity to differentiate between the 24/7 cityand the 24/7 society. Here, spatial relevance is the crucial criterion. It is highly plausible to assume that 24/7 is spatially very selective and prevails in different scales. There are quite a number of activities which have significantly extended – even if many rhythms are still rather traditional, as shown above – or are indeed 24/7. Besides traditional social and technical infrastructures – water utilities, electricity, sewage, police and emergency services, fire brigades –, 24/7 is most widely diffused among net based services. Many of these services are new or are indeed offered on a temporally extended basis – TV programs as an example have already been mentioned. This extension has been furthered not only by deregulation but also by the international integration of TV networks. But at the same time, TV is an example of a 24/7 service which has no or very little actual impact on public spaces. Watching TV takes place in private rooms, and the workforce (and related commuting) involved in nighttime TV delivery is rather small or even located in other time zones, with no nocturnal relevance. If we deal with 24/7 cities (or parts of cities) we have to look for spatially relevant impacts.

Chart 9 is a heuristic classification, in terms of their supposed spatial affinity, of functions or activities that are extended or are tending towards 24/7. The classification comprises four categories: remote locations which cannot be easily classified as either rural or urban; rural (because in agriculture extended work plays a major role); spaces in the vicinity of cities (where many former urban functions have been relocated); and, finally, the cities themselves. It is only a heuristic classification, meant to roughly categorize the locational affinities and, therefore, potential spatial implications of 24/7 functions. But it shows that extended or extending functions have very different spatial affinities. Especially services and traffic-related functions can be assumed to be concentrated in cities or their immediate surroundings (see chart 9). Depending on the clustering of extended activities but also on other factors (such as local demand, population density, and functional specialization of cities or parts of cities) the spatial impact could be very diverse. Here, a systematic empirical study is needed to allow for a spatial classification of temporal extension.

Regarding the change in the spatial affinities of temporally extended functions, it can be shown that at least some specialized types of production have migrated to the “periphery” – in more than one sense. Functions that once were urban have partly relocated to the periphery of the city or even to rural areas or have left Germany or other developed countries altogether – which has also contributed to a reduction of nighttime work. Big transport facilities – like ports or airports – are functions which used to be rather urban but due to structural changes (e.g. containerization) or to the growth of the facilities themselves have relocated to the more distant parts of agglomerations, even though they stay functionally closely related to the city. Here, the extent of nighttime work largely depends on the functional specialization and the regulatory framework (e.g. ban on night flights).

Changes in the division of labor in cities impact on the temporal extension of certain support functions. But to the same degree that some of these functions leave the city proper, the respective support functions also lose their clientele – e.g. bars and restaurants for nighttime workers (e.g. many of the diners in the USA). They are often replaced by fancier restaurants with more restricted opening hours (cf. BBC, 2012). But on the other hand, structural changes also create a demand for other types of nighttime functions (services, e.g. gyms, child care). Some cities develop a temporally extended specialization depending on their prevailing function: e.g. extended production vs. extended nightlife. The number of cities voluntarily specializing in extended urban nightlife seems to be growing: “One can even identify cities specializing in this 24/7 model, like Ibiza and Las Vegas. For most cities, the aim is to attract tourists, students and young professionals who are the main populations pushing for a widening of schedules to night time and the weekend. They are also the people who go out at night“ (Mallet, 2014: 5). Thus the cities maintain their claim for urbanity because the common perception is that “the only real cities are cities that are active at night. Provincial cities are ‘dead at night’” (Pincon and Pincon-Charlot, 2000, after Mallet 2014: 5). There even are some websites that single out cities as party destinations on a worldwide basis. In Europe Barcelona, Berlin, and Riga are among them. On these sites, too, the topos of the “city that never sleeps” is of the utmost importance. The following hint can be found on the internet: “’The city that never sleeps’ is a nickname given to 8 global 24 hour cities. Some may seem obvious but others not so” (brandneweyestravel, 2012; worldofwonder, n.d.; BBC, 2012). New York, Buenos Aires, Sao Paolo, Tel Aviv, Mumbai, Belgrad, Madrid, and Barcelona are explicitly mentioned. Furedi (2015) summarizes the tendencies as follows: “Some of the most successful international cities such as Barcelona, Berlin, New York or Sydney have enhanced their status and position because their cultural activities and experiences are perceived as vibrant and exciting. It is no coincidence that all these successful cities are also 24-hour environments” (Furedi, 2015: 6). Las Vegas and Miami (or at least major parts of them) also have an image of being 24/7 cities but only as tourist destinations for shopping and entertainment.

Berlin, too, is a city with a long partying tradition which dates back as far as to the “roaring twenties“ and was retained for West Berlin – being the only West German city without a curfew to attract tourists. Even in the 1920s, there already was fierce intercity competition for the crown of “sleeplessness”, as the following quote illustrates: “Maybe that the Broadway represented already in the 1920ies a metropolis, which never sleeps, but the real capital of the night was the Kurfürstendamm. Berlin awoke only in the evening: everybody believed it would be a pity to go to bed, before something unexpected happened. The critic Curt Moreck boasted ‘what’s the labyrinth of the Minotaur in comparison to Berlin at night’. The culture of Weimar was first of all a nocturnal one” (Davis, 2012).

The reference to the Kurfürstendamm indicates the spatial selectivity: Many party cities have one or more party miles where clubs and other entertainment venues with much extended opening hours cluster. These functions are sometimes truly 24/7 but, as I see it, they do not justify the label of a 24/7 city. Eberling and Henckel (2002) have developed a typology of spatio-temporal zones. One type – relating to the Italian discussion (Brioschi, 1997) – is called the “citadel of incessance”, i.e. a spatially limited zone of temporally highly extended activities (of different sorts). But even the existence of a 24/7 zone does not imply a 24/7 city. Moreover, some extended activities (e.g. call centers) have no spatial impact and therefore do not contribute much to the establishment of 24/7 zones.

Party miles could be interpreted as a specific manifestation of a “citadel of incessance”[9]. If they are characterized by spatial dispersion, fragmentation and a lack of connections, this is seen as a problem by some authors. For Bogota and Caracas, “night enclaves” are described which do not interconnect at all. Therefore, the night belongs to different zones (e.g. due to security reasons) (The Guardian, 2014). In the Night Manifesto this is described as a major problem and a violation of nighttime citizenship (Colaboratorio, 2014).

Some other – temporally and functionally very selective – extensions are related to special events which often extend deep into the night (and are promoted by the corresponding slogans): the long night of the museums, the long blade night, the long night of the sciences, etc. Even if these events are increasing in number all over the place and are promoted in line with the image of extended activities with the goal to gain a competitive edge over other cities, they essentially take place rather rarely and therefore do not seem very relevant for a decisive contribution to the 24/7 city.

Therefore, special attention should be directed to the differences between spatio-temporal zones: “As such, there is no singular night-time or evening economy, but rather a number of different economies running side-by-side, in support or opposition to each other. This is as true in terms of the ways different cities function at night, as it is for different parts of the very same city” (Roberts/Adam 2009: 11).

Nighttime Production and Productivity

A good indicator of the importance of the night could be the measurement of nocturnal economic power, i.e. the comparison of daytime and nighttime GDP. Time series could show to what degree a leveling has taken place. My hypothesis is that nighttime GDP has risen in absolute terms but that in relative terms, this rise is only slight. For obvious reasons, however – the lack of appropriate data and the methodological problem of generating them – this indicator will not be available in the near future.

But every now and then, there are publications which are heading in this direction, e.g.: “In 2009, the UK’s night-time economy was estimated to generate 27% of total urban turnover, while Sydney was able to create $2.7bn of economic benefits with only $127m spending on night-time management” (ARUP, 2015: 19). A recent study by the Night Time Industries Association claims that nighttime economy accounts for 6 per cent of the UK’s GDP and for about 1.3 million in terms of job generation (Furedi, 2015: 2 and 5).

Unfortunately, it is all but impossible to trace and check these claims. Moreover, they seem rather inconclusive. If it were indeed possible to generate an added value of 2.7 billion from an input of 127 million, no rational actor would fail to invest (this being a multiplier of 21,3)[10]. As the data and the methodology of their generation could not be qualified, it was impossible to evaluate their significance.

Final remarks, open questions

The evidence provided in this article offers a rather inconclusive – to say the least – picture of the development towards a 24/7 society or 24/7 city. 24/7 can be seen as a “fuzzy concept” (Markusen, 1999). The policy relevance of the topic – the night, and especially the urban night – is evident, and policy relevance is one of Markusen’s reasons to call for critical urban studies. But 24/7 has all the characteristics of a hardly identifiable and workable as well as empirically sustainable (“scanty evidence”) concept.

My conclusion is that 24/7 could be called a myth – in two different meanings:

• describing a social development which has little bearing on reality;
• providing a narrative to explain the development and make sense of it.

This narrative, in turn, comes in two versions:

• 24/7 as a horror scenario of the extreme version of capitalism sweeping away even the last resorts of non-commodified and non-economized niches of social life and natural rhythms – Crary being one of its exponents.
• 24/7 as a scenario of modernity, progress and the direction in which society should develop and to which it should adapt – the exponents being Moore-Ede and Kreitzman.

Therefore, the 24/7 discussion can be understood as a perspectivation of what the speaker wants to be seen. Depending on the perception and the political impetus, different aspects are taken into perspective, different claims are put forward – and this holds for both the scientific community and the planning practice. The night, and especially the urban night, is therefore a highly contested area.

Research on and planning of the nighttime have become rather fashionable in recent times. But the rediscovery of topics often goes hand in hand with the claim of first-hand discovery – thus, the authors of the introduction to the special issue of Urban Studies speak of the night blindness of planning research (Van Liempt et al., 2015: 407). Actually, a rather intense debate has already started some 20 years ago, while the seminal study by Melbin dates back to 30 years ago, the study by Schlör on Paris, London and Berlin to about 25 years ago.

The actual debate is almost exclusively focused on nocturnal entertainment economy. This is a way too restricted perspective. Even if there is no denying that tourism, leisure and entertainment are an important part of urban nighttime activities, this (spatially and temporally) selective focus does not justify the claim that there is a 24/7 city. Therefore, what is urgently needed is a comprehensive study of day and night.

Undoubtedly there are tendencies towards temporal extension, especially at the edges of the day, i.e. in the early morning or in the evening. It is also obvious that there are 24/7 functions, e.g. automated surveillance (with little personnel), and that they are increasing. Statistically, however, this does not translate into relevant leveling effects between daytime and nighttime employment. Most of the evidence concerning the differences between day and night and the respective rhythms in cities indicates that despite high degrees of freedom, humans remain diurnal primates, and collective rhythms – notwithstanding certain changes – remain more conventional and traditional than the talk about 24/7 would suggest. It seems that new developments – not yet thoroughly analyzed, but taken up by the media – are often interpreted as something revolutionary due to the intensity with which the topic is discussed or due to the number of researchers dealing with it. The preoccupation with a new topic sometimes leads to an overestimation of impacts and a neglect of context conditions and contradictory reflections or evidence. (It would be rewarding to test this hypothesis for several topics, e.g. telecommuting, the footlooseness of location decisions, smart city concepts.)

This is not to say that research on the nocturnal city is not a promising and relevant area of research, and that we already know everything – on the contrary. The structural changes, especially the increase in various conflicts ranging from the use of space to questions of social, spatial and temporal justice – “The working city, the sleeping city and the partying city do not always coexist peacefully“ (Gwiazdzinski, 2005: 132, after Mallet, 2014: 15) – are not yet adequately understood. More specifically, there is an urgent need to deal with conflicts and possible solutions. This contribution is also meant as a plea for a more comprehensive and integrated research of the urban day and night.

In its universality, the following quote is relevant: “A truly 24h city will be defined as a city that takes a holistic approach to the 24h cycle; a city in tune with natural rhythms and people’s ever changing personal and public desires” (ARUP, 2015: 14). The most important questions and conflicts become visible if one looks into the details of what 24/7 could mean. The analysis of the 24-hour and weekly cycles does not imply that we really deal with cities that are round-the-clock and round-the-week active and incessant, nor that there are similar levels of daytime and nighttime activities. Therefore, the focus needs to be more on specificities and differences, but also on the stability of the traditional night, which plays a much more important role than what is often suggested.

Therefore, some kind of verbal disarmament in the 24/7 debate seems in order, as well as a more distanced and reflective approach. Even in Crary’s book, more moderate statements can be found: “The homogenizing force of capitalism is incompatible with any inherent structure of differentiation: sacred-profane, carnival-workday, nature-culture, machine-organism, and so on. … Of course, people will continue to sleep, and even sprawling megacities will still have nocturnal intervals of relative quiescence” (Crary, 2012: 13). Remarkably, the notion of “intervals of relative quiescence” essentially seems to suggest that we are dealing with a high degree of incessance – which is precisely what is called into question in this article. Furthermore, it is unclear how strong the demand for 24/7 really is. In his review of Kreitzman’s plea for the 24/7 society, Fletcher (1999) observes: “In consequence, he (Kreitzman) exposes a profound flaw in his argument. He believes that because there is demand for a 24-hour society it will inevitably, eventually, happen. … Human beings want myriad things they cannot have, often because the social or economic price is unacceptable. I suspect the social price of a 24-hour society is unacceptable” (Fletcher, 1999)

This being said, 24/7 research would have to deal with a lot of questions whose empirical ground is thin or swampy:

• What is the long-term demand for temporal extension?
• What is the price of temporal extension and 24/7 – in economic, social, cultural terms?
• Who is willing to pay the price or is in the position to impose it?
• Which dimension of leveling between day and night might be realistically conceived, starting out from different assumptions?
• What type of protection does the night need?
• What national, cultural or geographic differences exist, what is their role and how are they going to change?
• What kinds and levels of distribution effects are related to temporal extension and 24/7?
• What does temporal extension and 24/7 mean for the temporally just city?
• What is the perception – in publications, the media, advertising – of different cities with respect to temporal extension, 24/7, “the city that never sleeps”?
• What are the concepts presented by different cities to promote the 24/7 city, and do these concepts also deal with the impacts?
• What are the most relevant differences between cities within one country, and between cities in different countries?

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[1] “Night work. Work done during usual sleeping hours and implying unusual sleeping times. The indicator covers work during the night for at least 50% of the days on which the person worked, during a four-week reference period before the survey interview” (Eurostat, 2015).

[2] If nighttime work is defined less strictly (e.g. only two hours during the night and not regularly but occasionally, the percentage rates of course increase: thus, the fifth report states that 19 per cent of EU27 are working at least two hours during the night (Eurofound, 2012: 41).

[3] A European comparison of opening hours of a discounter operating in all countries reveals massive between-countries differences, but 24/7 is not prevalent in any country (Kremer, 2015).

[4] Extreme types of childcare already existed in the industrial age. In the GDR, parents who were both in shiftwork could enroll their children in a Kindergarten of the enterprise for the whole working week. The children spent only their weekends at home. This kind of childcare was called into question rather early and was therefore restricted. At the time of German unification, Eisenhüttenstadt was the only city left with this type of 24-hour childcare (Großer, 2013).

[5] A personal inquiry at amazon Germany on the temporal distribution of orders, commissioning and delivery resulted in the answer: “Your questions touch information which we do not publish” (personal mail xx 2015).

[6] Interestingly, the introduction of the nighttime tube service in London is producing fierce conflicts because of the accompanying restructuring of the nighttime bus network.

[7] “In siesta cultures there is more tolerance towards late-night activities, since the siesta is an important buffer zone” (Steger and Brunt, 2003: 17).

[8] The Shanghai lighting regime differs between winter and summer. During the summer (May – September), nocturnal lighting (buildings, billboards, ads, screens – except street lighting) is restricted to the period from 7 pm to 11 pm, during the winter from 6 pm to 10 pm (http://www.shzj.gov.cn/art/2012/7/24/art_2824_4168.html Accessed 17^thAugust 2014). For Beijing, similar regulations are in place (http://wenku.baidu.com/view/0bddfc84bceb19e8b8f6ba0b.html accessed 17^thAugust 2014).

[9] “The city turns inside out at night. After the outflow of rush hour there is an hour’s pause before the inflow of recreational pilgrims’ streams back into the city’s core to fill the vacuum. The offices and buildings that teemed during the day stand empty while theatres, bars, discos, casinos, restaurants, opera houses, arcades, and concert halls begin to open. But only the core entertainment districts are active at night. Otherwise the city is quiescent, and the municipal business of street cleaning and emergency road and transit repairs takes place without hindrance of traffic” (Dewdney 2004: 89, after Straw 2014).

[10] In the study for Sydney (tbr et al. 2011), the fact that the study was not carried out by economists is pointed out right away, in the introduction and the executive summary.