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Calendars and Timekeeping
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Civil time is occasionally adjusted by one second increments called leap seconds. A detailed explanation of what a second actually is, and why leap seconds are necessary.
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Leap Seconds Civil time is occasionally adjusted by one second increments to ensure that the difference between a uniform time scale defined by atomic clocks does not differ from the Earth's rotational time by more than 0.9 seconds. Coordinated Universal Time (UTC...Extensive descriptions of many astronomical time keeping systems, with information on time zones and Julian day numbers.
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Astronomical Time Keeping Time keeping and construction of calendars are among the oldest branches of astronomy. Up until very recently, no earth-bound method of time keeping could match the accuracy of time determinations derived from observations of the sun and the planets. All...Information on date, time, and time zones from the New York Public Library.
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NYPLDR Time and Dates NYPLDR Time and Dates NYPLDR Time and Dates 1) Reckoning Days and Hours 2) Standard Time around the World...Second full moon in a month, or third full moon in a single season?
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Blue Moons Second full moon in month August 2005 Third full moon in a season of four full moons June 2007 Second full moon in month May 2008 Third full moon in a season of four full moons Dec. 2009 Second full...The calendar was the center of Maya life and their greatest cultural achievement. To carry out their astronomical calculations they developed a sophisticated mathematical system. The Maya Calendar website is developing with the intent of providing a complete view of Maya culture.
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The Maya Calendar by the Maya World Studies Center in Yucatan Mexico Calendar was the center of Maya life and their greatest cultural achievement. The Maya Calendar's ancestral knowledge guided the Maya's existence from the moment of their birth and there was little that escaped its influence. The Maya Calendar made by...Britannica.com explores the history of timekeeping, from sundials to cesium atomic clocks.
http://www.britannica.com/clockworks
Articles on the Gregorian and Julian calendars, the ISO date format, the Julian day number system, the Maya calendar, the Goddess lunar calendar, the Liberalia Triday Calendar and C functions for date conversion; plus software for calendrical conversion.
http://hermetic.nofadz.com/cal_stud.htm
The mathematics of the Chinese calendar. Explains the rules for the Chinese calendar.
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The Mathematics of the Chinese Calendar Year is the main holiday of the year for more than one quarter of the world's population; very few people, however, know how to compute its date. For many years I kept asking people about the rules for the Chinese...The mathematics of the Islamic calendar in Singapore.
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The Islamic Calendar Islamic calendar is based on visibility of the crescent Moon. This is a very difficult scientific problem. We know perfectly well where the Moon and the Sun are at any given time, but how light must the Moon be and...Questions and answers to satisfy the hearts of true millennium buffs.
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The difference between the Millennium and year 2000 The difference between the Millennium and year 2000 Short explanation The 3rd Millennium starts January 1st, year 2001 NOT year 2000 as many people believe, when using the Gregorian calendar. Year 2000 starts January 1st, year 2000. Longer explanation The...A proposal for a non-sectarian, culturally neutral calendar system.
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Empire of Atlantium Annus Novus Decimal Calendar Download pdf version of perpetual Annus Novus Calendar Download version 7.66 of Easy Date Converter software This easy-to-use application developed by the Acting Minister of Communications The Right Honourable Peter Meyer converts Gregorian years and dates into their Annus Novus...Applets related to calendars and keeping time, including sidererial time.
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Astronomy by JavaScript: Sun Calculators and More Scripts are computing solar data as sunrise, sunset, twilight, altitude, azimuth. JavaScript does not allow to perform any drawing operation, but clearly laid out tables can be set up and can be printed. Declination, Equation of Time and Length of...Published by Cambridge University Press. Gives a unified algorithmic presentation of the Gregorian, ISO, Julian, Coptic, Ethiopic, and Islamic civil calendars.
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The Calendarists This page has been visited times. Last modified:...Explains the difference between millenium and year 2000 as the absence of a year zero.
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Millennium Mistake On this web site we settle the millennium question once and for all: the clearly formulated argumentation leads among other things to the justification of the term millennium mistake keywords On this web site many things arise which have to...An explanation of the calendar including the origin of the day, week, month and year.
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The Calendar, Leap Years and the Year 2000 AD This page has been visited times since March 2, 1999 The Calendar, Leap Years and the Year 2000 AD Thanks to the Science and Engineering Research Council of the Royal Greenwich Observatory. This information is reprinted from files found in...A list of many American Indian tribe's names for months, days, and other calendar related information.
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Indian Moons, Days Other Calendar Stuff Over a long enough period of time, the moons will shift through the seasons. There are occasional multiple names for one moon or month. This could be caused by the overlapping of some moons in a month, different groups in...The worldwide interactive online astronomical/space calendar and calculator - for friends of astronomy, as well as astronomers.
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#1 Astronomical and Space Calendar CalSKY Select from menu above to long Table of Contents Current Topics See the International Space Station ISS as it silently transits the sky, or even crosses the Moon, Sun, or encounters/occults planets or stars. Transits during twilight make ISS an...Lunar calendar with lunations, from new moon to new moon, instead of months. Moon phase on each day. Chinese, Jewish, and Islamic months. Eclipses, meteors, planets, star charts. Christian, Pagan, Islamic, Hindu, and Jewish holidays.
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Paula Burch's Lunisolar Calendar (Lunar Calendar) 2005-2006 Can you even imagine time without breaking it up into seven-day weeks? Would you like to be more in touch with the seasons, planets, moon, and stars? Are you tired of calendars that often list the moon's quarters on the...Information on the origin of the week, and etymology of month and weekday names.
http://www.gkindia.com/holidays/weekdays.htm
Explanations of the Julian Calendar, the Gregorian Reform, the adoption of the Gregorian Calendar, the length of the tropical year and related matters.
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The Julian and Gregorian Calendars So with the solar calendar currently in widespread use. Originally the Romans numbered years ab urbe condita, that is, from the founding of the city (of Rome, where much of the character of the modern world had its beginnings Had...An explanation of the Julian day number system used by astronomers and calendricists.
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Julian Day Numbers Gregorian date is a date in the Gregorian Calendar, a Julian date is a date in the Julian Calendar Formore on these calendars see The Julian and Gregorian Calendars Astronomers sometimes use the term Julian date in another sense, according...An explanation of lunar, solar, lunisolar, rule-based and other types of calendars.
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Types of Calendar Moon provide temporal cycles which have strongly influenced the design of most calendars, which usually attempt to accord either with the solar cycle (the cycle of the seasons) or with the lunar cycle (the cycle of the phases of the...PlexGlobe is a productivity toolkit for global users and businesses that includes: - World clock and calendar such as Chinese and so on.
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PlexObject Solutions, Inc. PlexGlobe: Java based World Time, Clock, Calendar, Zone, NTP, Calculator, Sun, Moon Globe provides cornucopias tools to provide this information at your fingertips. WORLD CLOCK PlexGlobe comes with world clock (with day light saving support) that allows you to view current time for any part of the world. User can select location...The calendar has many options with a standard monthly interface, including: Sunrise Sunset, Moon phases and much more.
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Calendar with holidays and astronomical information. Prev Next month Thu Oct 27 01:19:19 2005 EST Calendar for October, 2005. Holidays: United States of America. Location: NewYork,NY Sunday Monday Tuesday Wednesday Thursday Friday Saturday 1 2 3 4 5 6 7...Complete guide to times in every time zone in the world.
http://GreenwichMeanTime.info
Explains the cosmological and astronomical influences in creating the Indian calendar.
http://senthilarumugam.tripod.com/id10.html