Time and Calendars on the net

Time

• Network Time Protocol
• Date and Time Gateway
• Directorate of Time (U.S. Naval Observatory - the official source of time used in the United States)
  • What time is it?
  • Systems of Time (explains TAI, UTC, UT0, UT1, etc.)
  • Systems of Time
• Greenwich Time: GMT
• Horology - The Index (The Science of Timekeeping, Clocks and Watches)
• Local Times Around the World
• Daylight Saving Time -- Saving Time, Saving Energy (Daylight Saving Time, Its History and Why We Use It)
• A Walk Through Time (A nice history of timekeeping. Also info on ancient calendars.)
• The Times of Our Lives: Investigations into Socio-chronology (The social aspect of time)
• Time (Leaflet No 27 of the Royal Greenwich Observatory)
• What Time is It? (Another astronomical perspective on time)
• NIST Time and Frequency FAQ Martian Time
• The Science of Timekeeping (An Application Note from Hewlett-Packard)
• End Daylight Savings Time (but they propose only two timezones for the continental US)
• GeoClock A shareware sun/moon clock with maps, world time, clocks, sunlight, twilight, sunrise and moonset)
• The official U.S. time (Select a time zone from a map and get the current time within a second accuracy)
• Daylight Saving Time (History, rationale, laws and dates - webexhibits.org)
• Clockworks: From Sundials to the Atomic Second (Measuring time - britanica.com)
• Timely tidbits (Milennium, atomic clocks, timeline - whyfiles.news.wisc.edu)
• The Quartz Watch (from the Smithsonian)
• What's the purpose of daylight saving time? (Straight Dope)
• The World Time Server ("World Time Server provides the most accurate current local times of any world clock on the Internet. It makes real time adjustments for Daylight Savings Time.")
• Time and the amateur astronomer (Sky and Telescope)
• WorldTime - The Ultimate Virtual Timepiece and World Clock (featureful free clock for PC)
• Internet Clock, Counter, and Countdown (lots of time-related links)
• NIST Time and Frequency Division Home Page ("users need to compare their own timing equipment to a reliable, internationally recognized standard. NIST provides this standard for the United States)
• NIST Internet Time Service
• What is a Leap Second? (U.S. Naval Observatory, Earth Orientation Department)
• humanclock.com
• Clocks That Won't Miss a Second in 20 Million Years (NY Times)
• All Days Are Not Created Equal (JPL Earth Features)
• The Stonehenge Pocket Watch
• The Time Travel Fund[tm] (invest in a fund to finance your time travel when it becomes possible)
• Equilibria - The Bank at the End of the Universe (why the above fund cannot work)
• What time is it? Well, no one knows for sure ("As the Earth spins slower, methods of telling time diverge. Experts warn this could endd in disaster" -- The Guardian)
• The Tick - WWV Bought by Clear Channel (humor)
• INDUSTORIOUS CLOCK ||| MONO*CRAFTS (requires flash)
• International Earth Rotation and Reference Systems Service (IERS) (The folks who decide when to add a leap second)
• The Time We Thought We Knew (Brian Greene on the illusion of time; NY Times)
• A Brief Note on Time Systems (Time: UTC, TAI, etc.; GPS; Date/time: ISO-8601, Julian)

Calendars

• Yahoo - Reference:Calendars

• DEC Answers Leap Year Complaint (Humorous: User claims year 2000 should not be a leap year)
• Astronomical Sky Calendar (generates a calendar which contains, for each day, the Julian Date, Sun rise & set times, Moon rise & set times and percent illumination, etc)
• Which years are leap years and can you have leap seconds?
• The year 2000 does not compute (CNN - Jan. 7, 1996)
• The Calendar Zone (Wow - everything to do with all kinds of calendars!)
• Gregorian-Hijri Dates Converter (Hijri is the Islamic calendar)
• Calendar (From Eric's Treasure Trove of Astronomy)
• How to determine the day of the week, given the month, day and year (from the sci.math FAQ) (From
• Gregorian Calendar (from Rice University's Galileo Project)
• The Equinoxes and Solstices (Leaflet No 74 of the Royal Greenwich Observatory)
• Calendars and their History (reprinted from the Explanatory Supplement to the Astronomical Almanac, P. Kenneth Seidelmann, editor)
• The Calendar FAQ ("Its purpose is to give an overview of the Christian, Hebrew, and Islamic calendars in common use. It will provide a historical background for the Christian calendar, plus an overview of the French Revolutionary calendar, the Maya calendar, and the Chinese calendar." -- Claus Tøndering, claus@tondering.dk)
• Hebrew Calendar Science and Myths (Good discussion of Hebrew calendar)
• What year numbering system was used in the time of Christ? (The Straight Dope, Cecil Adams)
• Calendars through the Ages (Our week, our year, calendars - webexhibits.org)
• The Russian Orthodox Church Calendar
• On This Day (NY Times)
• Assorted calendrical systems (brief discussion of many different calendars)
• Education World ? - Lesson Planning: Happy New Year! Or is it? ("That depends on which calendar you use!")
• Calendars of various cultures and religions (lots of odd calendars)
• One-World GLOBAL CALENDAR (Holidays, astronomical events, etc.)
• timeanddate.com (This site is not very accessible. For time functions, see "The Time Now" below.)
  • Useless dates related to your birthday
• The Time Now (A more accessible site than "timeanddate.com" with similar functions in terms of time, but not calendars)
• Leap day (My own page describing the formulas for calculating leap years in both the Gregorian and Russian -- also called the Revised Julian -- calendars)
• The home page of R.H. van Gent (some stuff on Easter, the International Date Line, several calendar systems)
• Calendar Links -- rudy.ca (lists of sites, programs, algorithms, etc.)
• Free Printable Calendar Templates (Word templates)

  Chinese calendar

• Chinese Calendar (China News Digest -- cnd.org)
• Western-Chinese Calendar Converter