calendrical system (thing) by Cyt

A way of keeping track of time - thereby arranging meetings and booking flights. Go back a loooong way. Just to do some senseless meta noding, calendrical systems include:

Jewish Calendar - featuring 12 or 13 months
Islamic Calendar - which started July 16, 622 AD
Hindu Calender - one of the oldest - more than 3000 years old
Indian Civil Calendar - the national calendar of independent India since 1957
Julian Calendar - made by Caesar
Roman Calendar - that gave us western people most of the names of the months
Egyptian Calendar - someone just got it right a long time ago
Babylonian Calendar - and some didn't
Mayan Calendar - don't try this at home
French Revolutionary Calendar - French people have always been wandering their own ways
Gregorian Calendar - can't live without it.
Chinese Calendar - dated back to 2637 BC
Aztec Calendar - a good Maya ripoff
Discordian Calendar - working 8 days a week is quite a blunder here

Discordian calendar	Egyptian calendar	Mayan Calendar	Indian Civil Calendar
French Revolutionary Calendar	Gregorian calendar	Julian calendar	Babylonian Calendar
Islamic Calendar	Chinese Calendar	Roman Calendar	Jewish Calendar
The Era of Caesars	"CE" and "BCE" are inaccurate terms	Aztec Calendar	calendar systems
Everything Perpetual Calendar	Calendrical	Don't try this at home	Hindu Calendar
Vedic star names	Tranquility Calendar	Cor!!	dating system