Vaishakha (Marathi: वैशाख) or Baisakha (Hindi: बैसाख) (Nepali: बैशाख) is a month of the Hindu calendar that corresponds to April/May in the Gregorian Calendar. It is the first month of the Nepalese calendar (the Bikram Sambat) and the Bengali calendar (Boishakh). In the Indian national calendar Vaisakha is the second month of the year, beginning on April 21 and ending on May 20.
In the Hindu solar calendar, Vaisakha begins in mid-April in Bengal, Nepal and Punjab. In Tamil Nadu, it is known as Vaikasi and represents the second month of the Tamil solar calendar. In the Hindu lunar calendar, Vaisakha begins with the new moon in April and represents the second month of the lunar year.
Vaisakha Purnima is celebrated as Buddha Purnima or the birthday of Gautama Buddha amongst southern Buddhists or the Theravada school. Purnima refers to the Full Moon. Known in Sinhalese as Vesak, it is observed in the full moon of May. Jallianwala Bagh massacre took place on the Punjabi New year day in Vaisakha Sukla Padyami.