Babylonian numerals names
1Īs this table shows, there are six years when a second month Addaru is added, and one year with an extra Ulûlu. It was introduced in 503 BCE by Darius I the Great (if not earlier). The Chaldaeans now started to look for a standard procedure for the intercalation of months. After Babylon had been captured by the Persian king Cyrus the Great in 539, priestly officials took over. From now on, intercalary months were still announced by the king, but he was advised by an astronomer. (The difference is only two hours.) The Chaldaeans concluded that seven out of nineteen years ought to be leap years with an extra month. The key was the discovery, in the mid-eighth century, that 235 lunar months are almost identical to 19 solar years. Because this happened ad random, this was not very satisfying, and the Babylonian astronomers (" Chaldaeans") started to look for some kind of regularity.
Originally, the king decided which month had to be added ("intercalated"), and when. In the table below, you will find the names of the Babylonian month and two calendars that were inspired by the Babylonian example. In the western calendar, this is solved by disconnecting the lunar phase from the calendar month the Babylonians found a different solution by adding leap months. Like all other calendars, the Babylonian calendar had twelve lunar months (about 354 days) and a problem to make these fit the solar year (about 365 days). Babylonian Calendar: the first calendar to use the "Cycle of Meton".