Greece

Independence Day, March 25. This event also celebrated in Cyprus. Anniversary of the beginning of the revolt against Ottoman rule in 1821. [what about april 6th?]
Ochi Day, October 28. On October 28, 1940, Greece entered World War II on the Allied side. This day gets its name from saying ochi (no) to the ultimatum of the Italian invaders.
Dumb Week, the week preceding Holy Week.
Saint Basil's Day, January 1. Basil was a bishop of Caesarea in the fourth century. Observed with the eating of Basil cakes.
Labor Day and Flower Festival, May 1.
Midwife's Day, January 8. Also known as Women's Day.
Clean Monday. Occurs on the first Monday in Lent, according to the Greek Orthodox calendar.

Public holidays   New Year's Day, Epiphany, Clean Monday, Independence Day, Good Friday, Holy Saturday, Easter, Easter Monday, May Day, Assumption Day, OXI Day [ochi day], and Christmas. Rhodes observes Dodecanese Accession Day (Mar 7). Xanthi observes Liberation of Xanthi (Oct 4). Thessaloniki observes St. Dimitrios Day.

Festivals of Ancient Greece

Gamelion, in January.
Anthesterion, in February.
Elaphebolion, in March.
Munychion, in April.
Thargelion, in May.
Scirophoriaon, in June.
Hekatombaion, in July.
Metageitnion, in August.
Boedromion, in September.
Pyanepsion, in October.
Poseidon, in December.