Who discovered the calender?

Question:

Who discovered the calender?

what was the person's name.....

Best Answer - Chosen by Asker: Calendars are a human construct, thus invented, not discovered. The western calendar in use today has its roots in ancient Egypt, which very early (circa 2000 BC) adopted a 360 day calendar with five extra days, to keep pace with the seasons. Earlier time keeping calendars in many cultures were based only on lunar phases, and ignored the seasons as unimportant (which they were prior to the development of agriculture).
Early Rome had a calendar of twelve months alternating 29 and 30 days, with an extra month every third year. Trouble was, the extra month was not automatic, only when the chief priest called for it. If he liked the top elected guys--extra month in your term fellas. If not, sorry, you're out early. This resulted in the first day of Spring, which was supposed to be March 25, wandering around into September!
Julius Caesar decided to clear up this mess and called in an ethnic Greek astronomer from Alexandria, Egypt, named Sosigenes. Sosigenes moved Spring back to March by having a "year" of over 450 days, and renamed one month for Caesar (July), with 31 days. He gave the year 365 days with a leap year every fourth year.
That made the year a bit too long, and by 325 AD Spring was March 21. No one cared, but that was the year the Council of Nicea set the rule for figuring out Easter (first Sunday after the first Full Moon following the first day of Spring). By the 1500s Spring was starting on March 11, putting Lent earlier. Eventually Christmas would have occured during Lent. Pope Gregory VIII decided to do something about this and called together the main astronomers in Europe to correct the problem. They dropped ten days out moving Spring back to March 21, and changed the rule for leap year so century years are leap only if divisible by 400 (like 1600). The Eastern Orthodox and Protestant countries ignored this, so for a couple hundred years dates changed when you crossed borders, but in the mid 1700s the Protestant countries one after another adopted this reform, although they had to drop eleven days by this point. (Thus Washington was born on Feb 11 old style but Feb 22 after the switch.)
So the inventors would be Sosigenes and the astronomers who worked for Pope Gregory.