A Tithi is the time the Moon takes to move 12 degrees relative to the Sun.
Each lunar month (Masa) has 30 Tithis.
Shukla Paksha (Waxing phase) refers to the period from New Moon to Full Moon (15 Tithis).
Krishna Paksha (Waning phase) refers to the period from Full Moon to New Moon (15 Tithis).
Tithi along with Masa are fundamental to determine festival dates.
Naming of Tithis
Amavasya is the moment of new moon.
Purnima is the moment of full moon.
All other Tithis are named using Sanskrit numbers: Pratipada (1st), Dwitiya (2nd), Tritiya (3rd), Chaturthi (4th), and so on.
Moon Phases
Use the slider to explore Tithis
Tithi Nuances
Tithis can start and end at any time, lasting between 18 to 24 hours due to the elliptical nature of the moon's orbit.
This makes it difficult to predict Tithi for a day without evaluating the moon's position at sunrise relative to the sun.
Due to historical conventions, the Tithi at sunrise is considered the Tithi for the day.