The Greyhawk Calendar is a fictional calendar used in the World of Greyhawk campaign setting for the Dungeons and Dragons role-playing game. It is the most common system for tracking the days and months of the Common Year in the Flanaess.
The Greyhawk year consists of 364 days, split into twelve months of twenty-eight days each, and four seven-day festivals, each placed at three month intervals. Different cultures in the campaign setting have their own names for the months and festivals. The months and festivals are commonly referred to as the Dozenmonth of Luna and the Four Festivals.
Days in Greyhawk are reckoned in weeks of seven days each. The days of the month are: Starday, Sunday, Moonday, Godsday, Waterday, Earthday, and Freeday. Godsday is commonly associated with worship, and Freeday with rest. The remaining days are considered "work days."
| Month | Common | Elven | Nomads | Season |
|---|---|---|---|---|
| Needfest | ||||
| 1 | Fireseek | Diamondice | Tiger | Winter |
| 2 | Readying | Yellowillow | Bear | Spring |
| 3 | Coldeven | Snowflowers | Lion | Spring |
| Growfest | ||||
| 4 | Planting | Blossoms | Frog | Low Summer |
| 5 | Flocktime | Violets | Turtle | Low Summer |
| 6 | Wealsun | Berrytime | Fox | Low Summer |
| Richfest (Midsummer) | ||||
| 7 | Reaping | Goldfields | Snake | High Summer |
| 8 | Goodmonth | Sunflowers | Boar | High Summer |
| 9 | Harvester | Fruitfall | Squirrel | High Summer |
| Brewfest | ||||
| 10 | Patchwall | Brightleaf | Hare | Autumn |
| 11 | Ready'reat | Tinklingice | Hawk | Autumn |
| 12 | Sunsebb | Lacysnows | Wolf | Winter |
An interesting feature of the Greyhawk calendar is that the days of the week always occur on the same day every year, a result of the year having a number of days divisible by seven.
The first of the month is always a Starday, and the rest follow as shown below:
The months and festivals are based on the cycles of Oerth's moons, Luna and Celene. Luna has a twenty-eight day cycle, while Celene's cycle is ninety-one days. Celene is full at the midpoint of each festival, while Luna is full at various times throughout the year. Notably, both moons are full on Richfest 3-5.