| 1. ACalendar.com |
| The calendar has many options with a standard monthly interface, including sunrise, sunset, and Moon phases. |
| http://www.acalendar.com/ |
| 2. Annus Novus Decimal Calendar |
| A proposal for a non-sectarian, culturally neutral calendar system. |
| http://www.atlantium.org/calendaran.html |
| 3. Astro Portal - CalSKY |
| The worldwide interactive online astronomical/space calendar and calculator - for friends of astronomy, as well as astronomers. |
| http://www.calsky.com/ |
| 4. Astronomical Time Keeping |
| Extensive descriptions of many timing systems, with information on time zones and Julian day numbers. |
| http://www.maa.mhn.de/Scholar/times.html |
| 5. Astronomy and Space Calendar |
| Features different views of the night sky, constellations, stars, planets, and other celestial wonders. |
| http://www.newarkmuseum.org/PermanentCollecti... |
| 6. Astronomy by JavaScript: Sun Calculators and More |
| Applets related to calendars and keeping time, including sidererial time. |
| http://www.jgiesen.de/astro/astroJS/ |
| 7. Blue Moon Myths |
| Second full moon in a month, or third full moon in a single season. |
| http://www.infoplease.com/spot/bluemoon1.html |
| 8. Britannica.com - Clockworks: From Sundials to the Atomic Second |
| Britannica.com explores the history of timekeeping, from sundials to cesium atomic clocks. |
| http://www.britannica.com/clockworks |
| 9. 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. |
| http://www.hermetic.ch/cal_stud.htm |
| 10. Calendars through the Ages |
| History and FAQs of calendars, from ancient Rome to outer space. Including Julian, Gregorian, Jewish, Islamic, Chinese, and Mayan. |
| http://webexhibits.org/calendars/ |
| 11. Calendopaedia |
| The encyclopaedia of calendars. |
| http://calendopedia.com/ |
| 12. Calendrical Calculations |
| Published by Cambridge University Press. Gives a unified algorithmic presentation of the Gregorian, ISO, Julian, Coptic, Ethiopic, and Islamic civil calendars. |
| http://emr.cs.uiuc.edu/home/reingold/calendar... |
| 13. GMT: Greenwich Mean Time |
| Complete guide to times in every time zone in the world. |
| http://wwp.greenwichmeantime.com/ |
| 14. Hindu Calendar Dates 52nd Century |
| Explains the cosmological and astronomical influences in creating the Indian calendar. |
| http://senthilarumugam.tripod.com/id10.html |
| 15. Indian Moons |
| A list of many American Indian tribe's names for months, days, and other calendar related information. |
| http://www.americanindian.net/moons.html |
| 16. Julian Day Numbers |
| An explanation of the Julian day number system used by astronomers and calendricists. |
| http://www.hermetic.ch/cal_stud/jdn.htm |
| 17. Leap Seconds |
| Civil time is occasionally adjusted by one second increments. A detailed explanation of what a second actually is, and why leap seconds are necessary. |
| http://tycho.usno.navy.mil/leapsec.html |