It is a well known fact that every Hindu temple ritual is being conducted on certain fixed and approved days of the month. These days' names can be found printed on each date-slip of a daily calendar. Do they belong to Astrology only? No, they have been so named simply, with respect to the phases of Moon only. They are called as Tithis (Lunar days, 'Thithis' in Tamil). For every thirty days these tithis repeat themselves. Among them there are two groups each having fifteen tithis.
