Social Jet Lag Overview: Researchers at Ludwig-Maximilians University in Munich, Germany use the phrase "social jet lag" to describe the problems caused by differences between people's internal biological clocks (also called people's circadian clocks, which reflect solar time) and the official clock time that society follows. As with ordinary jet lag, "social jet lag" can create problems with judgment and overall health.
These researchers find that people tend to align their basic activities, like sleeping, waking and eating, with the sun. Within a given time zone, people at the eastern edge tend to do these things, on average, earlier than people at the western edge. Moreover, along time zone boundaries, people tend to perform these activities at pretty much the same real time, even though their clocks are set an hour apart.
An extreme example of this phenomenon is offered by people in Spain, which is at the western edge of the time zone for most of continental western Europe. They tend to eat dinner much later than other people in this time zone, typically at 9:30 PM. Portugal, meanwhile, is just west of Spain and in a different time zone (Greenwich Mean Time, or GMT). There the customary dinner hour is 8:30 PM according to the local clocks, precisely the same moment in real time when the clocks strike 9:30 PM in Spain.
A principal finding of the research is that there can be significant social dislocations if clocks are more than 2 hours out of alignment with solar time. For a location on solar time, clocks will strike noon when the sun is at its zenith (apex or highest point) of the day.
Significance of Social Jet Lag to Financial Careers: People in operations jobs frequently are on shifts that put their work days, and thus their daily cycle of sleep and eating, many hours out of alignment with solar time and their internal biological clocks.
Many other financial services industry professionals similarly have work days that are aligned with trading hours in faraway securities exchanges. Examples of such professionals are:
A common scenario is that such professionals working in the U.S. must align their work days with the securities markets and exchanges in the East, which open at 9:30 AM Eastern, 8:30 Central, 7:30 Mountain, 6:30 Pacific, 5:30 Alaska and 4:30 Hawaii-Aleutian. Complicating matters further, some of these U.S.-based professionals need to be at work during all or part of the trading hours in such far-flung financial centers as London, Frankfurt, Singapore, Hong Kong and/or Tokyo. One of the oft-touted advantages of London as a financial center is that its position on the globe allows for partial alignment of its normal business hours with the closing hours in Tokyo and the opening hours in New York.
Social Jet Lag and Time Zone Consolidation: In some large countries, attempts to consolidate time zones to align working days across their territories can come at the price of serious social jet lag. When Mao Zedong and the communists took control of China in 1949, they decreed that the entire country would be on Beijing time. Previously, the nation spanned 5 time zones. Under the unitary time zone now in force, sunrise in the western edge of China can come after 10 AM in the winter.
As of 2009, Russian president Dmitry Medvedev has been advocating the idea of collapsing that country's 11 time zones into only 4. The theory is that greater overlap of business days across the nation, increasing economic efficiency. Sergei Smirnov, director of Moscow's Institute for Social Policy and Social and Economic Programs disagrees, asserting instead that having less than 8 time zones "could lead to a social catastrophe."
Daylight Saving Time and Social Jet Lag: Studies indicate a significant increase in accidents during the first week after the clocks change, and not just on the Monday immediately following. The effect is more significant in the spring when clocks move forward and most people lose an hour of sleep, but there also is a lesser spike in accidents when clocks move back in the fall, which results in the work day ending an hour later than before in real time.
Daylight saving time is supposed to reduce energy costs. Thus, several years ago the U.S. lengthened the period during daylight savings time is in force, starting it earlier in the year and ending it later. However, statistics compiled by a major utility in Russia indicate a mere 0.5% decrease in annual electricity usage attributable to daylight saving time.
Source: "Hour power," Financial Times, 12/23/09.
