Vesak: Buddha DayVesak is an important Buddhist festival celebrating the Buddhas' birthday, or, according to some Buddhists, the day the Buddha also reached enlightenment. The date changes each year around May or June, on the first full moon in the month of Veskha, according to the Buddhist lunar calendar. Many cultures celebrate differently, but common observance includes visiting a local temple, meditation and reflection, and decorating with lanterns.