The global economy is not a farm. In an industrial economy workers are assumed to live somewhere other than their place of business and regardless of whether workers are principals in the business, travel to and from work is safest in daylight. Daylight Saving Time shifts Mid-Day for optimum energy savings. It does not shift the duration of work/leisure/rest periods. A period of work expands out from the middle of the period.
In the Tropics, the regular amount of daylight available seems to allow for extended work hours as an economic (labor) advantage local to the area. This rationale has arisen time and again in defense of "peculiar institutions", La Cosa Nostra ("Our thing"), slavery, peonage and human trafficking. Modern Economics recognizes no "Tropical Production Advantage". Employees, unlike the more general class "Labor" are a non-fungible resource, and as such have a non-transferable location. The standards of Cultural Anthropology apply to semantic differentiation (and the Semantic Web).
Work, Leisure and Rest period durations are independent of Civil Twilight and the rising and setting of the sun.
For each location there are three graphs, and the dataset:
1. [Europe].[Russian Federation].[Central Federal District].[Moscow]
2. [Europe].[Belarus].[Minsk Region].[Minsk District].[Minsk]
3. [Europe].[European Union].[Ireland].[Dublin].[Dublin City]
5. [Australia and Oceania].[Australia].[New South Wales].[Lord Howe Island]
6. [Australia and Oceania].[Australia].[Australian Capital Territory].[Canberra]
8. [North America].[United States].[District of Columbia].[Washington]
9. [North America].[United States].[Arizona].[Pima].[Tucson]
10. [North America].[Mexico].[Distrito Federal].[Mexico City]
Work, Leisure and Rest period durations are independent of Civil Twilight and the rising and setting of the sun. The Latitude Effect makes comparisons of working hours (and other cultural mores) succeptible to an 'out-of towner' bias in an unfamiliar climate and environment. In a modern economy, all workers, even those in Professions must balance work (production) with leisure consumption to maximize the benefit to society-at-large.
The Longitude Effect is another name for Universal Coordinated Time (UTC) and time zones. This scheme allows you to set your watch to local time. Mobile devices often synchronize automatically to the time on local networks. It is quite likely that communications scheduling (Conference Calls) can be made equally transparent. It is possible, even likely, your great-grand-children will have to be taught the skill of setting a watch, for the same reason you have a hard time remembering the actual numbers on a speed-dial list.
Timekeeping has social and economic consequences, some very specific to an individual. These are the Latitude Effects.
1. Civil Twilight is used instead of Apparent Sunrise and Sunset. On the Winter Solstice, the difference is 60 minutes per day in Washington DC, US [a] and 58 minutes per day in Santiago (de Chile) [b]. The closer to the equator, the shorter the difference between Civil Twilight and Apparent Sunrise and Sunset. Closer to the poles, Civil Twilight gets longer in Summer and shorter, even disappearing, in Winter.
2. Toward the equator there is slightly less Civil Twilight compared to Apparent Sunrise and Apparent Sunset. For example, on Jun. 21 Singapore had about 12 minutes less daylight than Tucson. However the seasonal variation was much greater: Singapore sunrise 6:38AM, Tucson sunrise 4:49AM. On Dec. 22 Singapore sunrise will be 6:39AM (1 minute later) and Tucson sunrise will be 6:54AM (2 Hours 5 minutes later).
3. Individual Work schedules vary widely as do individual leisure time responsibilities. A regimented system is simply not feasible because there will always be special individual requirements. Local Authorities can insist upon uniformity in their respective jurisdictions, but they should not play favorites with social and economic consequences. On the one hand, this is not very fair, on the other, not very smart. A consequence of centering Comercial Hours around Mid-Day is that incremental additions (overtime) first subtract daylight leisure hours preferentially over darkness leisure hours. The closer to the equator, the the yearly variation in daylight/darkness becomes smaller and a fair distinction between work and leisure can only be made with a watch. Closer to the poles, the large yearly variation in daylight/darkness has, oddly, exactly the same effect, but only in Summer, since in Winter the sun provides an unmistakeable visual cue. In the Tropics, there is no such cue. All told, this leads to the misleading appearance of a time-based economic advantage of one region over another.