Krishna Janmashtami 

Krishna Janmashtami, also referred to as Krishnashtami, Janmashtami, or Gokulashtami, is an annual Hindu festival that commemorates the birth of Krishna, the eighth avatar of Vishnu. In certain Hindu scriptures, such as the Gita Govinda, Krishna is recognized as the supreme God and the origin of all avatars. The celebration of Krishna's birth takes place on the eighth day (Ashtami) of the dark fortnight (Krishna Paksha) in Shravana Masa (according to the amanta tradition) or Bhadrapada Masa (according to the purnimanta tradition), which coincides with August or September of the Gregorian calendar.

This festival holds significant importance, particularly in the Vaishnavism tradition of Hinduism. The celebratory customs associated with Janmashtami include a festival celebration, reading and recitation of religious texts, dance and enactments of the life of Krishna according to the Bhagavata Purana, devotional singing until midnight (the time of Krishna's birth), and fasting (upavasa), among other things. It is widely celebrated across India and abroad.

Etymology

So basically, "janmashtami" is a Sanskrit word that means "Krishna's birthday party"! It's made up of two words, "janma" which means birth, and "ashtami" which means eight. So, on the eighth day of the dark fortnight in August or September, we celebrate Krishna's birth!