Looking for something else, I found an old patch for wmcalclock I wrote three years ago. It adds a new feature called: "geek time".

You know, when you are a geek (or live like one), you sometimes live during night and sleep during sun time. My patch enables you to live your own way, free from you timezone. When you wake up (for example at 15:34), just middle-click in wmcalclock and it will reset itself to the hour you will have configured with the --wakeuptime option. From now, you will be able to follow your rythm of life: 15:34 is now wakeuptime for you (I usually used 9:00, which is default), and so on !

This is the ultimate home-timezone patch YOU need.

To add this patch to your favorite distribution package, use apt-build !

wget http://naquadah.org/~acid/patches/wmcalclock-geektime-acid.diff  && \
apt-build --reinstall -p 1 --patch `pwd`/wmcalclock-geektime-acid.diff install wmcalclock