Subject Guides     

Time Guide     

Time

• Official U.S. Time
  • From a number of U.S. federal government agencies.
• Time Service Department (U.S. Naval Observatory)
  • USNO Master Clock. Official source of time for the U.S. Dept. of Defense and the Standard of Time for the United States
• Greenwich Mean Time
  • Current GMT.

Time Zone Converter

• Time Zone Converter

Time Zones

• Coordinated Universal Time (UTC) (NASA)
  • Brief explanation of UTC and GMT (Greenwich Mean Time) and shows map to compute your time relative to the UTC.
• World Time Server
  • Find the local time of anywhere in the world.
• World Time Zone Map (U.S. Naval Observatory)

Calendars

• Calendar Zone
  • Many links to different calendars and information about them.
• Frequently Asked Questions about Calendars (Claus Tøndering)
  • Overview of the Christian, Hebrew, Islamic, French Revolutionary, Mayan, and Chinese calendars. Document in 3 formats: web pages, text file, and PDF file.
• see also Subject Guide on Astronomy

Calendars Converters

• Calendar Conversions (Scott E. Lee)
  • Convert dates from among Gregorian, Julian, Jewish and French Republic calendars.
• Julian Date Converter (U.S. Naval Observatory)
  • Converts from calendar date and time to Julian date, and vice versa.