Calendars and Timekeeping Astronomy Science.
A calendar is a system of organizing days for social, religious, commercial or administrative purposes. (wikipedia)
- The The Chinese Calendar www
The mathematics and rule explanation for the calendar. The Chinese Calendar.
- An Types of Calendars www
An explanation of lunar, Calendars, solar, lunisolar, rule-based and other calendars. Types of Calendars.
- A Indian Moons www
A list of many American Indian tribe's names for months, Moons, days, and other calendar related information. Indian Moons.
- The Maya Calendar 2000 www
The calendar was the center of Maya life and their greatest cultural achievement. Calendar 2000. 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. Maya Calendar 2000.
- An Julian Day Numbers www
An explanation of the Julian day number system used by astronomers and calendricists. Julian Day Numbers.
- A PlexGlobe: International Clock and Global Kit www
A productivity toolkit for global users and businesses that includes world clock and calendar. PlexGlobe: International Clock and Global Kit.
- Information World Holidays: Weeks and Months www
Information on the origin of the week, Holidays: Weeks and Months, and etymology of month and weekday names. World Holidays: Weeks and Months.
- An The Calendar, Leap Years and the Year 2000 www
An explanation of the calendar including the origin of the day, Calendar, Leap Years and the Year 2000, week, month and year. The Calendar, Leap Years and the Year 2000.
- Lunar Lunisolar Calendar www
Lunar calendar with lunations, Calendar, 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. Lunisolar Calendar.
- Complete GMT: Greenwich Mean Time www
Complete guide to times in every time zone in the world. GMT: Greenwich Mean Time.
- The ACalendar.com www
The calendar has many options with a standard monthly interface, ACalendar.com, including sunrise, sunset, and Moon phases. ACalendar.com.
- Civil Leap Seconds www
Civil time is occasionally adjusted by one second increments. Seconds. A detailed explanation of what a second actually is, and why leap seconds are necessary. Leap Seconds.
- Explanations The Julian and Gregorian Calendars www
Explanations of the Julian Calendar, Julian and Gregorian Calendars, the Gregorian Reform, the adoption of the Gregorian Calendar, the length of the tropical year and related matters. The Julian and Gregorian Calendars.
- Explains Hindu Calendar Dates 52nd Century www
Explains the cosmological and astronomical influences in creating the Indian calendar. Hindu Calendar Dates 52nd Century.
- Britannica.com Britannica.com - Clockworks: From Sundials to the Atomic Second www
Britannica. Clockworks: From Sundials to the Atomic Second.com explores the history of timekeeping, from sundials to cesium atomic clocks. Britannica.com - Clockworks: From Sundials to the Atomic Second.
- The Astro Portal - CalSKY www
The worldwide interactive online astronomical/space calendar and calculator - for friends of astronomy, Portal - CalSKY, as well as astronomers. Astro Portal - CalSKY.
- Extensive Astronomical Time Keeping www
Extensive descriptions of many timing systems, Time Keeping, with information on time zones and Julian day numbers. Astronomical Time Keeping.
- Articles Calendar Studies www
Articles on the Gregorian and Julian calendars, Studies, 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. Calendar Studies.
- The The Islamic Calendar www
The mathematics of the calendar in Singapore. The Islamic Calendar.
- Second Blue Moon Myths www
Second full moon in a month, Moon Myths, or third full moon in a single season. Blue Moon Myths.
- A Annus Novus Decimal Calendar www
A proposal for a non-sectarian, Novus Decimal Calendar, culturally neutral calendar system. Annus Novus Decimal Calendar.
- Questions The Difference Between the Millennium and Year 2000 www
Questions and answers to satisfy the hearts of true millennium buffs. The Difference Between the Millennium and Year 2000.
- Information Time and Date www
Information such as yearly and monthly calendars, and Date, counters, countdown, and the world clock which shows the current time in cities all over the world. Time and Date.
- Explains Millennium Mistake www
Explains the difference between millennium and year 2000 as the absence of a year zero. Millennium Mistake.
- History Calendars through the Ages www
History and FAQs of calendars, through the Ages, from ancient Rome to outer space. Including Julian, Gregorian, Jewish, Islamic, Chinese, and Mayan. Calendars through the Ages.
- Published Calendrical Calculations www
Published by Cambridge University Press. Calculations. Gives a unified algorithmic presentation of the Gregorian, ISO, Julian, Coptic, Ethiopic, and Islamic civil calendars. Calendrical Calculations.
- Features Astronomy and Space Calendar www
Features different views of the night sky, and Space Calendar, constellations, stars, planets, and other celestial wonders. Astronomy and Space Calendar.
- The Calendopaedia www
The encyclopaedia of calendars. Calendopaedia.
- A Archaeoastronomy www
A comprehensive introduction to archaeoastronomy including a look at various people groups and case studies of sites. Archaeoastronomy.
- The Dioptra www
The earliest dioptra (c. Dioptra.300 BCE) was a device for measuring the angle, in parts of a "Sign", between two celestial objects. Photos and descriptions of how to make one and how they work. Dioptra.
- A 54 Weeks in 2000 : Another Y2K Problem! www
A short discussion about week numbering, Weeks in 2000 : Another Y2K Problem!, showing how the ISO 8601 standard had fixed a Y2K problem, long before it was noticed in other non-ISO week-numbering schemes. 54 Weeks in 2000 : Another Y2K Problem!.
- A The Mathematics of the ISO 8601 Calendar www
A comprehensive document covering how week numbers are calculated using the ISO 8601 calendar system. Mathematics of the ISO 8601 Calendar. Includes links to many further resources. The Mathematics of the ISO 8601 Calendar.
- A The ISO Week Date Calendar www
A calendar of weeks based on the ISO 8601 week notation - convert any date into week number and day number. The ISO Week Date Calendar.
- Apple Mac OS X 10.0: How to Set Date and Time to ISO 8601:1988 Standard www
Apple support document. Mac OS X 10.0: How to Set Date and Time to ISO 8601:1988 Standard.
- Article Sky & Telescope: Dating van Gogh's Moonrise www
Article identifying the exact date and time of van Gogh's Moonrise painting, & Telescope: Dating van Gogh's Moonrise, based on Moon phase calculations. Sky & Telescope: Dating van Gogh's Moonrise.
- NASA's How long does each phase of the Moon last? www
NASA's Dr. long does each phase of the Moon last?. Marc of The Space Place answers questions about Moon phases and the lunar month. Includes GIF animation of the Moon going through its phases. How long does each phase of the Moon last?.
- International Quantum Candela: European Metrology Research Programme (EMRP) www
International project working towards the reformulation of the SI base unit the candela in terms of photon number. Candela: European Metrology Research Programme (EMRP). Quantum Candela: European Metrology Research Programme (EMRP).
- Resource Chair of Metrology www
Resource including quiz and examples of measurement, Metrology, decision making, compliance with specification, and comparison of two quantities. Maintained by a professor in electrical engineering in Osijek, Croatia. Chair of Metrology.
- Month Que Tal www
Month at-a-glance, Tal, what's up, planet watch, phases and encounters sun watch, and star maps and charts. Que Tal.
- The Observing www
The sky at a glance, Observing, highlights, sky chart, and gallery from Sky and Telescope Magazine. Observing.
- Provides Elegant Universe www
Provides introductory information about galaxies, Universe, the big bang, stars, the solar system, planets, asteroids, comets, astronomical events and astronomy related news. Elegant Universe.
- List Astronomical Pseudo-Science: A Skeptic's Resource List www
List of links for those, Pseudo-Science: A Skeptic's Resource List, who want to examine theories that are on the fringe of accepted scientific thought that are related connected to astronomy. A few examples are astrology, UFO's, the "Face" on Mars, and ancient astronaut theory. Astronomical Pseudo-Science: A Skeptic's Resource List.
- Alexa: Calendars and Timekeeping Astronomy
Alexa Directory Top Sites: Calendars and Timekeeping Astronomy
- DMOZ: Calendars and Timekeeping Astronomy
dmoz.org Directory: Calendars and Timekeeping Astronomy