I've been playing with local_date_time and time zones but don't understand the return values of utc_time(), local_time() and local_time_in(). Here's a small program: ---------- #include #include <iostream> int main() { boost::local_time::time_zone_ptr tz1(new boost::local_time::posix_time_zone("CET+1")); boost::posix_time::ptime pt1(boost::gregorian::date(2009, 1, 5), boost::posix_time::time_duration(12, 0, 0)); boost::local_time::local_date_time dt1(pt1, tz1); std::cout << dt1.utc_time() << std::endl; std::cout << dt1.local_time() << std::endl; boost::local_time::time_zone_ptr tz2(new boost::local_time::posix_time_zone("CET+2")); std::cout << dt1.local_time_in(tz2) << std::endl; } ---------- The output of this program is: 2009-Jan-05 12:00:00 2009-Jan-05 13:00:00 2009-Jan-05 14:00:00 CET The program uses CET which is the abbreviation for Central European Time which is UTC+1. If the UTC time is now 12:00:00 the local time in CET+1 must be 14:00:00 (and not 13:00:00). Accordingly the local time in CET+2 must be 15:00:00. Why Boost.DateTime appends "CET" to the local time in CET+2 I don't understand either. Is this a bug or do I misunderstand these functions? Boris