Calendar Zone Calendars. Of all kinds and cultures and from all eras.
Time (Official US: Pacific Time Zone) Click arrows fro other time zones.
VPC — 20th and 21st Centuries VPC - Virtual Perpetual Calendar. Find the day of the week a date in the past, or future, falls upon.
NIST Physics Laboratory Time & Frequency Division The National Institute of Standards and Technology (NIST) page has a variety of services for verifying time and frequencies for computer clocks, radio stations, power companies, and more. This site includes a Time and Frequency from A to Z (Glossary).
Astronomical Information Center From the U.S. Naval Observatory, includes World Time Zone map..
A Walk Through Time This is an overview of the history of timekeeping maintained by the National Institute of Standards and Technology (NIST). Beginning with an explanation of various ancient calendar systems, the site then discusses early clock, modern time-keeping methods, and time zones.
Historical Timeline “Here you will find 5 timelines featuring some of the key events, inventions, and leaders which had a major impact on the world's history.”