timezone database discrepancy
I am calculating start/end time of the daylight savings time using tz_database and default timezone database file "date_time_zonespec.csv" that comes with boost 1_44. I found discrepancy between results of the calculation for "America/Chicago" region and published data. for years 2010-2007 the results match. However, for the 2006 calendar year, published results from several sources are: Start: April 2 End: October 29 and calculated results are: Start: March 12 End November 5 I will appreciate any advise/comments on how to deal with this issue.
I found discrepancy between results of the calculation for "America/Chicago" region and published data.
for years 2010-2007 the results match. However, for the 2006 calendar year, published results from several sources are: Start: April 2 End: October 29 and calculated results are: Start: March 12 End November 5
The calculated dates are correct. The United States changed the rules in 2007 (to start the second Sunday in March and end the first Sunday in November): http://en.wikipedia.org/wiki/Energy_Policy_Act_of_2005#Change_to_daylight_sa... John This e-mail message and any attachment(s) transmitted with it are intended only for the use of the recipient(s) named above.This message may be privileged and/or confidential. If you are not an intended recipient, you may not review, copy or distribute this message. If you have received this communication in error, please notify us immediately by e-mail and delete the original message.
On Tue, 5 Oct 2010, John Wilkinson wrote:
I found discrepancy between results of the calculation for "America/Chicago" region and published data.
for years 2010-2007 the results match. However, for the 2006 calendar year, published results from several sources are: Start: April 2 End: October 29 and calculated results are: Start: March 12 End November 5
The calculated dates are correct. The United States changed the rules in 2007 (to start the second Sunday in March and end the first Sunday in November): http://en.wikipedia.org/wiki/Energy_Policy_Act_of_2005#Change_to_daylight_sa...
It would seem like the code should use the old rules for 2006 and earlier, though, rather than the new rules. -- Jeremiah Willcock
John Wilkinson
Start: April 2 End: October 29 and calculated results are: Start: March 12 End November 5
The calculated dates are correct. The United States changed the rules in 2007 (to start the second Sunday in March and end the first Sunday in November): http://en.wikipedia.org/wiki/Energy_Policy_Act_of_2005#Change_to_daylight_sa... g_time
John, Do you know if it is possible to configure timezone class to follow historical rules when such rules exists instead of overwriting history with the most recent DST rule?
participants (3)
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archie14 -
Jeremiah Willcock -
John Wilkinson