The Hindu ritual year is determined
according to both a solar calendar and a
lunar calendar. Aside from the Gregorian
calendar and the common era, there are
two indigenous Hindu calculations of
the solar year, both of which have twelve
solar months. In northern India these
months correspond to the twelve signs
of the zodiac, and the months change as
the sun moves through them. As in the
Western zodiac, the year begins when
the sun enters Aries, although according
to Indian astrology this transition takes
place around April 14, rather than
March 21, as figured in Euro-American
astrology. In southern India there is an
identical solar calendar, whose names
are drawn from the names of certain
nakshatras or lunar asterisms. Aside
from the solar months, the solar year is
also divided into halves based on the
movement of the sun: the Uttarayana
for the period when the sun is moving
north, and the Dakshinayana in the
time the sun is moving south. The sun
begins its northward journey, considered the more auspicious time, on
Makara Sankranti, reckoned as falling
on January 14; it begins its southward
journey six months later on Karka
Sankranti on July 14.
Far more important for religious
purposes is the lunar calendar, which
has twelve lunar months: Chaitra
(March–April), Baisakh (April–May),
Jyeshth (May–June), Ashadh (June–July),
Shravan (July–August), Bhadrapada
(August–September), Ashvin (September–
October), Kartik (October–November),
Margashirsha (November–December),
Paush(December–January), Magh(January–
February), and Phalgun (February–
March). In northern India, the calendar
usually begins in the first day of the
bright half of Chaitra, meaning that the
last days of the year are those in the
dark half of this same month.
Since these lunar months are based on
the phases of the moon (ending with the
full moon in northern India and the new
moon in southern India), the festivals
determined by this lunar calendar fall at
different times each year with respect to
the solar calendar. This is because the
twelve lunar months are completed in
about 354 solar days, and thus, each lunar
year begins eleven days earlier than the
last. About every 21⁄2years this discrepancy
is corrected by the addition of an extra
lunar month, known as the intercalary
month, through which the solar and lunar
calendars are kept in general correspondence. The intercalary month is added to
any lunar month in which the sun does
not enter a new sign of the zodiac and can
thus fall in any month of the year. In this
way, although the solar calendar is less
important in everyday life, it helps maintain the general correspondence between
the lunar calendar and the seasonal festivals associated with that calendar.
At least in northern India, the three
major seasons (hot, monsoon, and cool)
have important links with the festival
calendar. In general, the most ritually
active time is the cool season between
October and February; in many places
this is also the time following the
harvest, when many people have more
time and money to spend on religious
observances. The hot season has many
rites associated with heat, whereas the
rainy season, as a time of peril, is often
connected with rites of protection.