A 2027 observances calendar lists Magha Puja on Sunday 21 February. Theravada temples, especially in Thailand, Laos, Cambodia and Sri Lanka, hold candle processions for the gathering of the sangha. Vesak, in May, is the other widely kept full moon. Rohatsu was 8 December. Laba was 15 January.
Thaipusam in January was a Tamil vow to Murugan. The page is this moon and not a class for sale.