Annus Novus Decimal Calendar
A proposal for a non-sectarian, culturally neutral calendar system. |
Astronomical Time Keeping
Extensive descriptions of many astronomical time keeping systems, with information on time zones and Julian day numbers. |
Astronomy by JavaScript: Sun Calculators and More
Applets related to calendars and keeping time, including sidererial time. |
Blue Moon Myths
Second full moon in a month, or third full moon in a single season? |
Britannica.com - Clockworks: From Sundials to the Atomic Second
Britannica.com explores the history of timekeeping, from sundials to cesium atomic clocks. |
Calendar Conversions
A handy tool for converting to and from various calendars, including the Jewish calendar and the French Republican calendar. |
Calendar Studies
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. |
Calendars through the Ages
History and FAQs of calendars, from ancient Rome to outer space. Including Julian, Gregorian, Jewish, Islamic, Chinese, and Mayan. |
Calendopaedia
The Encyclopaedia of Calendars. |
Calendrical Calculations
Published by Cambridge University Press. Gives a unified algorithmic presentation of the Gregorian, ISO, Julian, Coptic, Ethiopic, and Islamic civil calendars. |
Islamic Calendar
Islamic months begin at sunset on the day of visual sighting of the lunar crescent. This site discusses the concept of the International Lunar Date Line and contains numerous maps of crescent visibility. |
Leap Seconds
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. |
LunarCal - A Perpetual Chinese Lunar Calendar
LunarCal is a 160-year perpetual Chinese Lunar Calendar for 1900 to 2060. Chinese festivals are listed and the moon phase is displayed. |
Lunisolar Calendar
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. |
Maya Calendar 2000
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 comp |
Month Calendar for Any Year
Create a calendar, month poetry, how the months got their names, day names in different languages, birthstones, gemstones, Roman gods and the blue moon. |
The Calendar, Leap Years and the Year 2000
An explanation of the calendar including the origin of the day, week, month and year. |
The Chinese Calendar
The mathematics of the Chinese calendar. Explains the rules for the Chinese calendar. |
The Difference Between the Millennium and Year 2000
Questions and answers to satisfy the hearts of true millennium buffs. |
The Islamic Calendar
The mathematics of the Islamic calendar in Singapore. |
Time and Date
Lots of time and date related information, such as yearly and monthly calendars, counters, countdown, and the world clock which shows the current time in cities all over the world. |
Time and Dates
Information on date, time, and time zones from the New York Public Library. |
World Holidays: Weeks and Months
Information on the origin of the week, and etymology of month and weekday names. |
