Reference: Calendars and Time

Time

Celestial

Chinese

Conversions

Holidays

Islamic

Jewish

Roman

Time

U. S. Naval Observatory Time Services Department

http://tycho.usno.navy.mil The official time source for the Department of Defense and the standard of time for the United States, this site also offers time zone information as well as sunrise and sunset calculations. See also the home page of the National Institute of Standards and Technology: Time and Frequency Division. For the really technical stuff on the earth's rotation and its effect on the measurement of time, see the International Earth Rotation Service (IERS).

Celestial

Astronomy: What's UP This Month?

www.learnwhatsup.com/astro Important astronomical events, along with monthly star charts, are featured on this site for sky watchers. Included are sun and moon rise, transit, and set times as well as links to other WWW astronomy pages. See also Skywatching Center and Skycalendar.

The ESO Sky Calendar Tool

www.eso.org/observing/proposals/skycalc.html This site provides a calculation tool for determining sun rise and set times, astronomical twilights, and moon rise and set times and phase for each night of the month.

The Planets

www.astro.wisc.edu/~dolan/Planets For any year between 1900 and 2100, this site will generate a list of what constellation each planet is in for each month out of the specified year.

Sun and Moon Data

http://riemann.usno.navy.mil/AA/data/docs/RS_OneDay.html On this site you can obtain the times of sunrise, sunset, moonrise, moonset, transits of the sun and moon, and the beginning and end of civil twilight, along with information on the moon's phases (using a location or longitude/latitude designation).

U. S. Naval Observatory Data Services

http://aa.usno.navy.mil/AA/data Just as you would expect, this site provides complete and accurate data on solar and lunar events, eclipses, planetary positions, and other sidereal data.

Virtual Reality Moon Phase Pictures

http://tycho.usno.navy.mil/vphase.html This site can display an animation of the phases of the moon for any date and time during the years 1800 to 2199 A.D. See also Moon Phase.

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Chinese

Chinese Calendar Home Page

www.cnd.org/Other/calendar.html The 2000 Chinese calendar can be printed from this site, along with solar to lunar and lunar to solar conversions.

Western-Chinese Calendar Converter

www.mandarintools.com/calconv.html Just what the name says.  There are also useful links to other WWW sites on the Chinese lunar calendar.

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Conversions

Calendar Conversions

www.calendarhome.com/converter This WWW page allows you to convert dates among various calendar systems, including Julian, Gregorian, Jewish, and French republican.

Calendrical Calculations

http://emr.cs.iit.edu/home/reingold/calendar-book/index.shtml This is the home page for the book by Nachum Dershowitz and Edward M. Reingold, Calendrical Calculations (1997). In addition to a large calendar converter, there are links to a variety of useful calendar WWW sites.

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Holidays

The American Secular Holidays Calendar

www.smart.net/~mmontes/ushols.html Holidays affecting work schedules (federal holidays and observances, banking holidays) are calculated, along with other common holidays, from the late 18th century.

Encyclopedia of Days

www.shagtown.com/days An ambitious individual project, this page describes holidays around the world, including all major religions. A calendar conversion utility is included.

Interfaith Calendar

www.interfaithcalendar.org From 2000 to 2005, this site provides the principal holidays for many of the world's religions.

Seasonal Festivals of the Greeks and Romans

www.cs.utk.edu/~mclennan/BA/SF/SF.html Just what the name says.

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Islamic

Interfaith Calendar

www.interfaithcalendar.org From 2000 to 2005, this site provides the holidays for many of the world's religions, including Islam.

Regional Islamic Calendar

www.ummah.org.uk/ildl/zone3 By world region, shows expected lunar visibility using Ilyas' criterion of crescent sight ability. Includes links to related WWW sites.

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Jewish

Interfaith Calendar

www.interfaithcalendar.org From 2000 to 2005, this site provides the holidays for many of the world's religions, including Islam.

The Hebcal Interactive Jewish Calendar

www.hebcal.com/hebcal Generate a calendar of Jewish holidays for any year 0001-9999 and customize candle lighting times to your zip code, city, or latitude/longitude. See also The Jewish Calendar.

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Roman

Calculation of the Ecclesiastical Calendar

www.smart.net/~mmontes/ec-cal.html This site includes a program for calculating Easter Sunday in both the Western and Orthodox traditions. It also provide dates for other feasts in the Catholic calendar as well as other moveable feasts associated with Easter in the Western and Eastern traditions. There are references to both printed and online resources relevant to the dating of ecclesiastical events over time.

Interfaith Calendar

www.interfaithcalendar.org From 2000 to 2005, this site provides the holidays for many of the world's religions, including Christianity.

Seasonal Festivals of the Greeks and Romans

www.cs.utk.edu/~mclennan/BA/SF/SF.html Just what the name says.

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