\Greek calendar\
1. Any of various calendars used by the ancient Greek states.

Note: The {Attic calendar} divided the year into twelve
      months of 29 and 30 days, as follows: 1. Hecatomb[ae]on
      (July-Aug.). 2. Metageitnion (Aug.-Sept.). 3.
      Bo["e]dromion (Sept.-Oct.). 4. Pyanepsion (Oct.-Nov.).
      5. M[ae]macterion (Nov.-Dec.). 6. Poseideon
      (Dec.-Jan.). 7. Gamelion (Jan.-Feb.). 8. Anthesterion
      (Feb.-Mar.). 9. Elaphebolion (Mar.-Apr.). 10. Munychion
      (Apr.-May). 11. Thargelion (May-June). 12. Scirophorion
      (June-July). A fixed relation to the seasons was
      maintained by introducing an intercalary month, ``the
      second Poseideon,'' at first in an inexact way,
      afterward in years 3, 5, 8, 11, 13, 16, 19 of the
      Metonic cycle. Dates were reckoned in Olympiads.

2. The Julian calendar, used in the Greek Church.