A Live Clock Made of Google Earth
The Google Earth Clock is a live clock that displays the current local time using satellite imagery from Google Earth.
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Windows Tip: Find the Day of the Week for any Given Date Very Quickly
Learn how to find the day of the week for any past or future date with your Windows Calendar / Clock in Vista or Windows 7.
Sync Windows Clock with Internet Time Server
If you have an Internet connection, Windows can automatically synchronize your clock with Internet time servers to keep it accurate.