Calendars

What year is it and when will the next millennium begin? It all depends on what system of measuring time you use. While those using the Gregorian calendar are preparing to celebrate the year 2000, the Chinese calendar reports that it is the year 4636, the Hebrew calendar says it is 5760 and the Islamic year is 1421. Explore the history of measuring time and how calendars reflect not only astronomical studies but also cultural heritage, religious beliefs and historical events through the direct links on the Times Launch Point Web site: https://www.latimes.com/launchpoint.

Level 1

Calendars: Counting the Days: What is a calendar and how have calendars been used throughout history? Trace the development of calendars through such cultures as the ancient Babylonians, Egyptians and Aztecs up to the present day and learn about units of time measurement, including how the 21st century will begin Jan. 1, 2001.

https://www.worldbook.com/fun/calendars/html/calendars.htm

KIDPROJ Multicultural Calendar: Explore holidays from around the world and discover how many countries celebrate New Year’s Day at different times of the year.

https://www.kidlink.org/KIDPROJ/MCC/

Origins of the Months: The month of January gets its name from the Roman god Janus, who represented doors and new beginnings. Discover the meanings behind the names of the months of the Gregorian year.

https://tqjunior.advanced.org/4626/month.htm

Level 2

World Calendars: When the new year starts all depends on what calendar system you use. Learn about the history behind a range of calendars: the Gregorian, the Jewish, the Islamic, the Thai, Japanese, Hindu, Ethiopian and Native American.

https://www.transimage.com/Cal/CalMain.html

An Introduction to Calendars: Why do months have different numbers of days? Find out through this site that discusses the astronomical and historical reasons behind how different calendars are calculated, including a debate that has historical figures arguing about the accuracy of a 360-day year divided into 12 30-day months.

https://ghs1.greenheart.com/billh/intro.html

Calendars: A solar calendar such as the Gregorian calculates the year to be in line with the seasons, a lunar calendar such as the Islamic calculates months using the phases of the moon, and a lunisolar calendar such as the Hebrew and Chinese calendars considers both the phases of the moon and the seasons in its determinations. Compare different calendar systems, learn how leap years are calculated and explore calendar history through this informative site.

https://www.sunspot.noao.edu/PR/answerbook/calendar-main.html

Level 3

Web Exhibits: Calendars: The concept of a day is based on the rotation of the Earth on its axis, while a year is based on the revolution of the Earth around the sun. Learn how astronomy is used to calculate different types of calendars and explore how different cultures throughout history have developed tools and methods for measuring time.

https://www.webexhibits.com/calendars/calendar.html

Calendopaedia--The Encyclopaedia of Calendars: Find out the history behind different calendars, learn about systems for measuring time and compare 20 calendars in a handy matrix.

https://www.geocities.com/CapeCanaveral/Lab/7671/

Martindale’s Reference Desk: Calendar Calculators: Use this collection of online calculators to help you convert dates into different systems, ranging from ancient Aztec and Mayan to present day Chinese, Hebrew and Islam calendars.

https://www-sci.lib.uci.edu/HSG/RefCalculators1.html#CAL

EXPLORER’S QUEST

The answer to this Internet quiz can be found in the sites at right.

According to the Gregorian calendar, will the year 2000 be a leap year?

CLUE: See Calendars

Find What You Need to Know: Have a project on California history? Need help doing a math problem? Launch Point now covers more than 100 topics for getting your schoolwork done. Go to https://www.latimes.com/launchpoint/ for the full list of subjects and direct links to the best Internet sites.

Answer to last week’s Quest: The astrolabe helped sailors determine their position by using the quadrant to measure the altitude above the horizon.

Launch Point is produced by the UC Irvine department of education, which reviews each site for appropriateness and quality. Even so, parents should supervise their children’s use of the Internet. This column was designed by Anna Manring.