Horas 

Horas helps you keep track of the time around the world by letting you create several clocks corresponding to different time zones. Horas has many features including the automatic adjustment of your computer clock.
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DS Clock 

DS Clock is a digital desktop clock that displays variable date, time, and time zone information built from the format string. It allows you to fully customize its look and feel, and can synchronize your computer's clock with Atomic Time Servers.
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TrayDay 

TrayDay: today's date at a glance, in the Windows tray, with handy popup calendar. Can show week numbers to ISO (or your own) standard. A double-click types the date in the format of your choice. Julian Day and Internet Time features.
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