Hello, While tracking a weird timezone bug present in Mac OS X and Darwin, I determined the bug lies in the tzcode package. I'm not sure when the bug first appeared but the affected versions include tzcode2010{j,k}.tar.gz at the minimum. The problematic part is settzname() function in localtime.c. When USG_COMPAT flag is set it initializes timezone and altzone variables, but since it (incorrectly) assumes the last non-DST rule is current it assigns a wrong value to them. For a counter-example see Asia/Seoul timezone: in this case timezone should be UTC+9:00 but set to UTC+8:00 instead. As far as I concerned the code is also present in FreeBSD and Darwin, and in Darwin it produces a wrong result for strftime(3) call as a consequence. (I'm going to report this issue to Apple separately.) Regards, Kang Seonghoon