History of Dharmashastra (Ancient and Mediaeval Religious and Civil Law in India) v6.c82.631.2

v6.c82.631.2

The synodic month is a little over 29½ days, while the tropical year is a little less than 365¼ days. These are incommensurable periods. For ordinary life and calendars whole days are required; besides, the starting of the year and the month must be properly defined and must correspond to seasons and some era-must be used. These are the requirements of a calendar which has to be used for civil and religious purposes The complexity of calendars is due mainly to the incommensurability of the above two astronomical periods. The Moslems solved it by ignoring the length of the tropical year and holding fast by the Moon as the measurer of time. They had a purely lunar year. The result was that the Moslems' year was of 354 days and that in about 33 years all their festivals travelled through all the months of the year. On the other hand, the ancient Egyptians ignored the moon as the measurer of time and their year was of 365 days (12 months of 30 days each plus five epagomenal, i. e. additional days). Their priests stuck to this system for 3000 years, they had no leap years or intercalary months. Most ancient peoples including Indians followed a luni-solar calendar and tried to adjust the lunar months to the solar year by the system of intercalary months. It has been seen above (p. 489 note 710) that even the Ṛgveda speaks of an additional month (in I. 25 8) but how it was arrived at and where in the scheme of months it was introduced we do not know.