Lunar Months

There are twelve lunar months called Masas which are named after the star constellation on the full-moon day of each successive month. They are:

Month Star
Chaitra Chittra
Vaishakha Visakha
Jyeshta Jyeshta
Ashada Poorvashada
Sravana Sravana
Bhadrapada Poorvabhadra
Aswayuja Aswini
Kartika Krittika
Margashira Mrigashira
Pushya Pushyami
Magha Makha
Phalguna Uttara-Phalguni

Each month is divided into two parts: the brighter half and the darker half. The brighter half called the Shukla paksha starts after the new-moon day and extends to the full-moon day when the Sun and Moon face each other. This is the period of the waxing moon. The darker half is known as the Krishna paksha which commences after the full-moon day and ends with the new-moon day. This represents the waning moon.

An year known as Samvathsara , which is made up of twelve months, has two sections, each consisting of six months. They are called Ayanas . The period during which the sun seems to travel northwards, from Capricorn rasi to Gemini rasi is called Uttarayana , whereas the period between Cancer and Sagittarius is known as Dakshinayana when the sun appears to move southwards. They are called declination.

An year is further divided into six parts, each part consisting of two months, on the basis of the six seasons called Ritus .

They are :

Month Season (Ritu)
Chaitra and VaisakhaVasantha (spring)

Jyeshta and Ashada
Greeshma (Summer)
Sravana and BhadrapadaVarsha (rainy season)
Aswayuja and KarlikaSharad (autumn)
Margashira and PushyaHemanta (winter)
Magha and PhalgunaSishira (Dewy)