
I'm not sure what the optimal time difference with Europe would be when you're working from over here - but the 9 hours between California and Sweden really makes my life tricky.
Pretty often I have to stay up late for an early morning meeting Swedish time, and then get up really early for an early afternoon meeting Swedish time - thus my sleep hours are squeeze together to mere few hours.
If I get down to my office at 8 am, which isn't really early, but not really late, it's 5 pm in Stockholm. Since most people at the office in Stockholm don't live in the office as I do, they actually have to leave and go home, pick up kids, get food etc (my commute is about 15 seconds - and there is never rush hours), so I usually only have about an hour or so before people start being unavilabe. Thus - I try to get up earlier to get some more time. But the earlier I get up, the more "groggy" I am.
But usually, these few hours are not enough, and I need to catch them in the morning. 8 am in Stockholm is 11 pm here. If I stay up later, I have even more chances of catching them - must people are in by 9 am... midnight here. But the later I stay up, the more "groggy" I am.
Sometimes I wonder what some of my colleagues think of me... "oh, it's that groggy woman calling again, yawning and sounding really sleepy"...
(Screenshot of my dual clocks on my Google Sidebar - so I can keep track of the time in Sweden when it's really early or really late and I can't calculate time...).