[Boost-users] 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.