A problem related to using time zones in the schedule to build jobs periodically:

GMT-10 is the same timezone as US/Hawaii. Both, at 12:00 are 00:00 at CEST Time Zone.

If you set this in the Schedule textarea of a build configuration:

TZ=US/Hawaii
00 12 * * *

The next execution is at 00:00 CEST => OK

But, if you set this:

TZ=Etc/GMT-10
00 12 * * * 

The next execution is at 04:00 CEST => WRONG

It seems to be a bug when specifying time zones with GMT-XX.