Wednesday, March 24, 2010

Does Anyone Know What Time It Is?

In my job I have to deal with five time zones, four of which observe summer time at some point in the year. The team I manage sits in the following time zones:
  • Central European Time (CET) - 1 hour ahead of UTC
  • North American Eastern Standard Time (EST) - 5 hours behind UTC
  • North American Central Standard Time (CST) - 6 hours behind UTC
  • North American Pacific Standard Time (PST) - 8 hours behind UTC
  • Hawaiian-Aleutian Standard Time (HAST) - 10 hours behind UTC
UTC is Coordinated Universal Time. All of the time zones I need to deal with deal with summer time except for HAST. In the summer, I need to deal with the following time zones:
  • Central European Summer Time (CEST) - 2 hours ahead of UTC
  • North American Eastern Daylight Time (EDT) - 4 hours behind UTC
  • North American Central Daylight Time (CDT) - 5 hours behind UTC
  • North American Pacific Daylight Time (PDT) - 7 hours behind UTC
  • Hawaiian-Aleutian Standard Time (HAST) - 10 hours behind UTC
However, they don't all change at the same time. The North American summer times start on the second Sunday of March and end on the first Sunday in November. Note that this only went in to effect in 2007 in the United States. The Energy Policy Act of 2005 amended the Uniform Time Act of 1966 and extended the daylight saving time period. Prior to 2007, daylight saving time in the US started on the first Sunday in April and ended on the last Sunday in October.

CEST is another story. CEST starts on the last Sunday in March and runs to the last Sunday in October.

Scheduling meetings in March is frustrating because 9 different time zones end up being used during the month. The start of summer time was never aligned between the US and Europe, but we used to both end on the same day.

In the United States, if you live in Hawaii or Arizona or any of the US territories, you don't have to deal with this crap (except that you do when working with people in other time zones). But it is nice having the same local time throughout the year.

If you live in Indiana, I do not know how clocks work for you.

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