The Onam 2022 celebrations started on August 30 with Atham. The main festival is later celebrated over four days, which starts nine days after Atham. While Thiruvonam 2022, the most important day of Onam, falls on the second day of the main Onam festivities on September 8, the third day of Onam, Avittam, will be celebrated on September 9 this year.