Moon's play - Waxing and Waning!

In the past adamant children were fed by mothers at dinnertime showing the mesmerizing moon on the sky; children too stopped their crying and chewed in the food seeing the charm of the moon. Children seem to be indulging in these thoughts: why this moon is not stable and goes on changing day by day - waxing sometimes and waning sometimes! OK. Now, why there are these waxing and waning in Moon?

Tithis, the rule of Hindu families!

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.