In the World of Greyhawk, the Common Year, or CY, is the basis of the common calendar. Years occurring before the Common Year are denoted with negative numbers, or are sometimes listed as "BCY" (Before Common Year).
There is no Common Year zero (0 CY), as the reckoning began with the first year, 1 CY, which must be accounted for when converting other systems of reckoning years prior to 1 CY, such as the Baklunish Hegira (BH), Flan Tracking (FT), Oeridian Record (OR, also known as the Oerid Reckoning), the Olman Lunar (OL), the Olven Calendar (OC), Suloise Dating (SD), or the Touv Calendar (TC).
Days, weeks, and months within the Common Year are reckoned using the Greyhawk Calendar.
The Common Year Reckoning is an Oeridian, specifically an Aerdi, creation, and replaced the Oeridian Record. The Common Year was established as the system of reckoning by Grand Prince Nasran I of the Great Kingdom of Aerdy in 645 OR (1 CY), when he declared universal peace throughout his the land, and took the title of Overking.
- Baklunish Hegira: 2660 BH (Folio.5)
- Flan Tracking: 2151 FT (Folio.5)
- Olven Calendar: 4463 OC (Folio.5)
- Olman Lunar: 805 OL (tSB.64)
- Oeridian Record: 645 OR (Folio.5)
- Suloise Dating: 5116 SD (Folio.5)
- Touv Calendar: 1408 TC (tSB.64)
- Baklunish Hegira: 3235 BH (Folio.5)
- Flan Tracking: 2726 FT (Folio.5)
- Olven Calendar: 5038 OC (Folio.5)
- Olman Lunar: 1380 OL
- Oeridian Record: 1220 OR (Folio.5)
- Suloise Dating: 6091 SD (Folio.5)
- Touv Calendar: 1983 TC
- Baklunish Hegira: 3250 BH (LGG.13)
- Flan Tracking: 2741 FT (LGG.13)
- Olven Calendar: 5053 OC (LGG.13)
- Olman Lunar: 1395 OL (tSB.64)
- Oeridian Record: 1235 OR (LGG.13)
- Suloise Dating: 6106 SD (LGG.13)
- Touv Calendar: 1998 TC
For results of 0 or less, subtract 1 from the result. In rare cases where the initial date is negative, convert to an older reckoning first. If this is not possible (such as with a negative SD date), then subtract 2 from the result (ie, once for each lack of a zero year).
BH date - 2659 = CY date.
FT date - 2150 = CY date.
OC date - 4462 = CY date.
OL date - 804 = CY date.
OR date - 644 = CY date.
SD date - 5515 = CY date.
- 6106 SD - 5515 = 591 CY
- 5094 SD - 5515 = -421 - 1 = -422 CY
- -500 SD - 5515 = -6015 - 2 = -6017 CY
TC date - 1407 = CY date.
Date determination within the Common Year reckoning
To determine the date for a specific number of years spanning both BCY (Before Common Year) and CY, it is essential to account for the lack of a zero year. This is done in a similar manner to converting dates from another reckoning.
- For x years before a CY date, subtract 1 if the result is 0 or lower.
- 591 CY - 591 = 0 - 1 = -1 CY
- 591 CY - 600 = -9 - 1 = -10 CY
- For x years after a BCY (Before Common Year) date, add 1 if the result is 0 or higher.
- -422 CY + 422 = 0 + 1 = 1 CY
- -422 CY + 500 = 78 + 1 = 79 CY
- -----. World of Greyhawk Fantasy Game Setting. Lake Geneva, WI: TSR, 1983.
- Holian, Gary, Erik Mona, Sean K. Reynolds, and Frederick Weining. Living Greyhawk Gazetteer. Renton, WA: Wizards of the Coast, 2000.