Abstract
This work analyzes time use surveys from 19 countries (17 European and 2 American) in the middle latitude (38–61 degree) accounting for 45% of world population in this range. Time marks for primary activities are contrasted against light/dark conditions. The analysis reveals winter sunrise synchronizes labor start time below 54 degree, occurring within winter civil twilight. Winter sunset is a source of synchronization for labor end times. Winter terminator punctuate meal times in Europe: dinner occurs 3 h after winter sunset time within 1 h; 40% narrower than variability of dinner local times. The sleep-wake cycle of laborers is shown to be related to winter sunrise whereas standard population’s appears to be irrespective of latitude. The significance of the winter terminator depends on two competing factors average labor time (~7 h30 m) and the shortest photoperiod. Winter terminator gains significance when both roughly matches. That is within a latitude range from 38 degree to 54 degree. The significance of winter terminator as a source of synchronization is also related to contemporary year round time schedules: the shortest photoperiod represents the worst case scenario the society faces.
Highlights
Background colors display ambient light conditionsThe lightest background shows the region where light prevails irrespective of calendar date
This work is aimed to an analysis of human primary activities time marks extracted from time use surveys in seventeen European countries and two American countries which cover 45% of the world population living in the middle latitude range from 38° to 61°
Relevant time marks for the budget of time can be retrieved from the so-called daily rhythms where the shares of the sample doing a prescribed activity are shown as a function of time on an average day
Summary
The lightest background shows the region where light prevails irrespective of calendar date. It is bounded by the winter terminator, which is piece-wise linear in winter daytime (see Equation (4)) with slopes α = ±30 min/h (minutes of change in sunset or sunrise time per hour of change in photoperiod), a value to keep in mind. Darkest background shows the region bounded by the summer terminator which sets the shortest night year round and has been delayed by one hour to simulate daylight saving time (a biannual, seasonal change in Δ), which is enforced in the regions analyzed in this paper with exceptions of Saskatchewan (Canada) and Arizona (United States). Intermediate background displays region where light or darkness seasonally alternates. Straight values of φ would have rendered them curvilinear as in any web page that shows a day/night map of the Earth
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
