Book of Indian Eras, with Tables for Calculating Indian Dates c13.29

c13.29

The old Greek year consisted originally of 360 days, divided into 12 months of 30 days each. But as many of the Greek festivals depended on the moon, it was soon discovered that the true length of a mean lunation was about 29½ days, and that of a solar year about 365 days. Various methods were adopted from time to time for accommodating the computation by lunar months to the solar year. In the time of Perikles the enneateris, or cycle of 8 solar years, was in use. This consisted of 8 lunar years of 354 days each, with the addition of 3 intercalary months, in the 3rd, 5th, and 8th years, making a total of 99 lunations or lunar months. But as 8 solar years of 365¼ days contain 2922 days, while 99 lunations of 29½ days amount to only 2920½ days, there was a deficiency of one day-and-a-half in every cycle of 8 years.