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.