From Hellenion’s December 2022 Calendar: Poseideon-Poseideon 2 (Year 2 of the 700th Olympiad) – Haloa, December 20; Heliogenna, December 21-22; Hekate’s Deipnon, December 24; Noumenia of Poseideon 2, December 25; Agathos Daimon, December 26. Remember all festivals begin at sundown of the day before. See our calendar page for more information about each occasion.