The evening before Christmas — the start of Christmas celebrations in many traditions.
Christmas Eve, the night before Christmas Day, marks the start of Christmas celebrations across most Western Christian traditions. Many families attend midnight Mass, exchange gifts, or share a special meal together. In Latin America, Spain, and parts of Europe, Christmas Eve (Nochebuena) is the principal celebration rather than Christmas Day itself.
Computed for Orsay (Europe/Paris) using local sunrise, sunset and astronomical positions.