At Automattic I have coworkers across many time zones. As a result I usually base time references on GMT instead of my local time zone. This gets a bit confusing in Google Calendar, which I have set to my local time zone. Then Alex Concha, one of my VaultPress teammates, mentioned that Google Calendar supports showing multiple time zones. It takes just a minute to setup and you end up with an additional hour column.
The ‘World Clock’ in Google Calendar Labs is also useful for seeing the current time in multiple time zones while working inside your calendar.
One more thing in Google Calendar I use to manage multiple time zones is the ‘Quick Add’ form. It supports things like “10pm GMT Test out Google Calendar on 19 Mar 2013”. Calendar will pick up on the GMT reference and set the event to your local time zone. In my case that would be 4pm local time.
Multiple time zones and day light savings can make scheduling a widely distributed team more of a headache, these features in Google Calendar make it a bit less painful.