Vaikasi Visakam is said to be the day when Lord Muruga / Subramanya incarnated in this world with the mission of saving earth from demons like Soorapadman. The Vaikasi Visakam is celebrated in a grand manner in Murugan Temples (Swamymalai, Tiruchendur). Valli Kalyanam is celebrated in Murugan Temples on Vaikasi Visakam day.
The divine creation of Lord Subrahmanya, also known as Skanda, Karthikeya or Murugan, to alleviate the sufferings of the Devas is believed to have occurred on Vaikasi Visakam. (Visakam is one of the 27 Nakshatras).