With Google calendar that's very easy, there's an option to specify different time zones for a single event's start and end times. It's also very useful that y

With Google calendar that's very easy, there's an option to specify different time zones for a single event's start and end times. It's also very useful that you can set the left margin (in the web app) to show two different time zones in a "ruler" format. So even if your overseas appointments for later in the week are displayed in terms of your current timezone, a quick glance across will confirm what their "local" time will be once you're on the ground.