February 25, 2007 - Are You Ready to Spring Ahead?
As part of the Energy Policy Act of 2005, most of the United States and Canada will be changing the start and end of Daylight Saving Time soon. (Note that at this time, Mexico will not be changing their Daylight Saving Time period. Windows operating systems are introducing a new set of Mexican Time Zones to account for this).
From 1987 through 2006, Daylight Saving Time started on the first Sunday in April, and ended on the last Sunday in October.
But from now on, clocks will be moved 1 hour forward on the second Sunday in March, and back 1 hour on the first Sunday in November. For 2007, that translates to March 11th and November 4th.
Newly-released operating systems (such as Windows Vista) will already have the new calendar in place, and will automatically account for the change. Others, will need to be patched. Most vendors have already released these patches, or will soon do so.
Some older versions of operating systems, however, will not have patches, and will this have to be manually adjusted.
In addition some devices will built-in calendars/clocks could have problems (PDAs, phones, etc).
Here are a few dates and times to consider as you plan any testing:
- 03/10/2007 (any time)
- 03/11/2007 00:00:00
- 03/11/2007 00:00:01
- 03/11/2007 00:01:00
- 03/11/2007 01:59:59
- 03/11/2007 02:00:00
- 03/11/2007 02:00:01
- 03/11/2007 02:01:00
- 03/11/2007 02:59:59
- 03/11/2007 03:00:00
- 03/11/2007 03:00:01
- 03/11/2007 03:01:00
- 04/01/2007 02:00:01 (former DST start date)
- 04/01/2007 02:01:00
- 04/01/2007 03:00:00
- 04/01/2007 03:01:00
- 10/28/2007 01:59:59 (former DST end date)
- 10/28/2007 02:00:00
- 10/28/2007 02:00:01
- 10/28/2007 02:01:00
- 10/28/2007 03:00:00
- 10/28/2007 03:01:00
- 11/03/2007 (any time)
- 11/04/2007 00:00:00
- 11/04/2007 00:00:01
- 11/04/2007 01:59:59
- 11/04/2007 02:00:00
- 11/04/2007 02:00:01
- 11/04/2007 02:01:00
- 11/04/2007 02:59:59
- 11/04/2007 03:00:00
- 11/04/2007 03:00:01
- 11/04/2007 03:01:00
- 03/08/2008
- 11/02/2008
Here are some links for further reading:
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