Greyhawk Rules - Savage Tide
We will be using Real World names for the days and months, since everyone is not familiar with the World of Greyhawk.
Here is the link to the Greyhawk Calendar
You will note that there are 12 months, each with a corresponding Real World month. Fireseek is January, Readying is February, and so on. The one week periods every three months are festivals, with appropriate celebrations.
Also note that the day of worship is in the middle of the week, and the last day of the week is a day of rest. Half of all the shops are closed on that last day, except for taverns, inns, and brothels.