Greetings! I would like to use boost::date_time to convert between U.S. time zones and GMT, with dates spanning the year-2007 change of rules. There is a "custom time zone", but that takes a Posix string which, if I understand correctly, can't handle both pre- and post-2007 simultaneously. I did see a dst_calc_engine, but there doesn't seem to be a way to connect that to a dst_day_calc_rule, at least not a method standardized in the library. Am I missing something? I guess I could just derive from dst_day_class_rule and override the start_rule_as_string() and stop_rule_as_string() to be something "random"? Thank you in advance. The Boost libraries really are wonderful. (Although I guess us users tend to only write when we hit a wall :-)). Thanks! -Mike