Description of Problem: mktime seems to treat tm_isdst oddly. They are surely the same time? The difference between the mktime calls is that for the former, tm_isdst is set to 0, while for the latter it is -1. If I try 'BST' (with tm_isdst==1), I also get -3600. Version-Release number of selected component (if applicable): glibc-2.2.4-19 How Reproducible: 100% Steps to Reproduce: 1. date --date="1970-01-01 00:00 GMT" +%s 2. date --date="1970-01-01 00:00 UTC" +%s Actual Results: [tim@cyberelk tim]$ date --date="1970-01-01 00:00 GMT" +%s -3600 [tim@cyberelk tim]$ date --date="1970-01-01 00:00 UTC" +%s 0 Expected Results: Both should return 0, I think, since both times refer to the same instant. Additional Information: In /etc/sysconfig/clock ZONE is "Europe/London".
Confirmed still present in 8.0
A little bit of British history: the UK was on UTC+1 from 1968 to 1971. See http://student.cusu.cam.ac.uk/~jsm28/british-time/. Therefore the result you see is exactly right.