Purnima (also called Poornima, Sanskrit: पूर्णिमा) is the Indo-Nepalese word for Full Moon. The day of Purnima is the day (Tithi) in each month in which the full moon occurs, and marks the division in each month between the two lunar fortnights (Paksha). The Shukla ("bright") Paksha is the fortnight before, and the Krishna ("dark") Paksha is the fortnight after, Purnima.
Vat Purnima is celebrated on the full moon day of the month of Jyeshta. Women pray for their husbands by tying threads around a banyan tree (Vat) on this day. It honors Savitri, the legendary wife of Satyavan who escaped death for her husband's life. It is the chosen day for worshipping Yama deva
Guru Purnima, devotees offer puja (worship) to their Guru, on a full moon day. This is well known as Vyasa Purnima (Sanskrit. व्यास) after the birthday of the celebrated author of Mahabharata who is declared as the guru of all in the Shiva Purana.
Sharad Purnima or Kojagiri purnima, the Autumn Harvest Festival, on a full moon day.
Buddha Poornima, the day of birth, enlightenment and passing away of Gautama Buddha, on a full moon day.
Holi/Phalgun Purnima, the Spring Festival of Colours in Hinduism/Buddhism/Jainism, the full moon day in the month of Phalgun.