First some useful articles on the history of calendars: Gordon Moyer's "The Gregorian Calendar" SCIENTIFIC AMERICAN (May 1982) plus Reader Response letter (August 1982) Colin Wilson's (ed.) The Book of Time (Westbridge Books, 1980) plus any Ency. under subjects such as "Calendar" or "Time Measurement" plus if you can find it, look for Nichole Vick's "Getting a Yearful" in ALDUS MAGAZINE (Nov/Dec 1992) which has a great historical perspective on the development of calendars.
Second, a little information to whet your appetite for further research (which would make a good topic for students at most levels). The Romans used months based on lunar cycles (30 or 29 days in length), leading to a calendar of 10 months (295 days). March was their first month, with September, October, November and December their 7th, 8th, 9th, and 10th months respectively. January and February were added as the final two months in 700 B.C. Eventaully, the calendard shifted from lunar connections, and in 46 B.C. Julius Ceasar made important changes, triggered by an initial "the last year of confusion." The changes included adjustment to approximately 365 days, adjustment of month cycles to fit the vernal equinox, and rearrangement of the months so January became the first month (shifting the other months so that theur prefixes did not match their order). Finally, in 1582, Pope Gregory XIII made the final reform, setting the average calendar year to be 365.2425 days, leading to the creation of leap years.
As to the Month names, January is named after Janus (god of beginnings), February is derivative of Latin word for purification (a new year custom), March was named for the god Mars, April is derived from a LAtin word meaning "to open" as buds of a year, May perhaps was named for either the goddess Maia or dedicated to old people ("maiores"), July and August represent the efforts of Julius and Augustus Ceasar, and the remaining fit a numerical prefix pattern.
Hope this helps....keep searching as there is so much left out there...such as why the days are arranged in a week the way they are, how days got there names, how 10 days were skipped in a calendar in 1582 (when October 5 was declared to be October 15), how the French made an effort to change the calendar system in the early 1800's and failed, and finally the use of modular arithmetic to determine days of a week for any Gregorian date. Have fun exploring....
Jerry Johnson Math department Western Washington University
On Tue, 24 Oct 1995, Sam Evers wrote:
> Eileen, > > Thanks for ruining my day. Now I'm going to be thinking about > "months" all day long. It has never occured to me that September, > etc. were named with prefixes. The only explanation I can see is that > these months were indeed seven through ten on some calendar at some > time. However, if ANYONE has an explanation that they are certain of, > please post it for Eileen's students and for my sanity. > > > On 10/23 Eileen was talking about prefixes: > > >One of the students said - The months of the year - September, > >October, November, December, and began saying that is the same as the > >months. September is the 7th month. Suddenly several of the students > >said - no its not its the ninth month. The next question was - Why > >are the prefixes used differently with the months? Or, has there > >ever been a time when September was the 7th month of the year? Or, > >when were the months named, and were they intentionally named using > >these pre-fixes? > >