Hindu Lunar calendar is called the Panchang ("The five
Limbs"). The lunar calendar is based upon the daily rising
and setting of moon and on it's waxing and waning characteristics.
The lunar month is divided into two fifteen-day parts.
Beginning with the new moon (Purnima), the subsequent
fifteen days culminate in the full moon and are called
waxing or bright fortnight (Shuklapaksha).
The next fifteen days following the full moon culminate
in the new moon (Amaavasya) and are called waning or dark
fortnight (Krishna Paksha). Each day of the month is associated
with either the bright fortnight or the dark fortnight.
The lunar year consists of twelve months of thirty days
each. The calendar adds an extra month once every five
years to correct for the difference between the solar
and the lunar year.
names of the month of the lunar year are : Chaitra (March
- April), Vaisaka (April - May), Jyeshtha (May - June),
Ashadha (June - July), Sravana (July - August), Bhadrapada
(August - September), Asvina (September - October), Karttika
(October - November), Agrahayana (November-December),
Paush ( December-January), Magha (January-February) and
Phalguna (February-March). In the calendar, the days of
the week are believed to be governed by deities.
Sunday is ruled by Sun(Ravi) and is called Ravivar('var'
means day), Monday is called Somavar and is ruled by the
moon(Soma),Tuesday or Mangalvar is ruled by Mars (Mangal),Wednesday
is ruled by Mercury(Budh),hence Budhvar ,Thursday is ruled
by(Brhaspati) and is called Brahaspativar, Friday or Shukravar
is ruled by Venus(Shukra) ,and Saturday is ruled by Saturn(Sani)
and is called Sanivar.