I imagine most people in the States will know about this, but those of us elsewhere who interact with the US regularly may not know about Extended Daylight Savings Time.
DST in the US has traditionally gone from the first Sunday in April to the last Sunday in October. This is almost, but not quite, the same as here in the UK, so for the majority of the year, California is eight hours away, except for one week, when it’s nine.
From 2007, US DST is being extended by roughly one month, in an experiment which is expected to show substantial energy savings. For 2007, DST will run from Mar 11 to Nov 4.
Anyone planning meetings conference calls in the spring might need to know about this… and make sure that any software they use knows about it too!