Common Year
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.

History
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.
Conversions
| To CY | To OR | To OL | To TC | To FT | To BH | To OC | To SD | |
|---|---|---|---|---|---|---|---|---|
| From CY | — | +644 | +804 | +1407 | +2150 | +2659 | +4462 | +5515 |
| From OR | -644 | — | +160 | +763 | +1506 | +2015 | +3818 | +4871 |
| From OL | -804 | -160 | — | +603 | +1346 | +1855 | +3658 | +4711 |
| From TC | -1407 | -763 | -603 | — | +743 | +1252 | +3055 | +4108 |
| From FT | -2150 | -1506 | -1346 | -743 | — | +509 | +2312 | +3365 |
| From BH | -2659 | -2015 | -1855 | -1252 | -509 | — | +1803 | +2856 |
| From OC | -4462 | -3818 | -3658 | -3055 | -2312 | -1803 | — | +1053 |
| From SD | -5515 | -4871 | -4711 | -4108 | -3365 | -2856 | -1053 | — |
Note: None of the calendars of Oerth use a year zero, which complicates date conversion involving negative years since standard mathematics assumes a zero. This occasionally confuses even formal historians. The solution is to add 1 when converting from a negative date to a positive, and to subtract 1 when converting a positive date to a negative. If both dates are negative, no adjustment is necessary.
Examples
1 CY
- 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)
576 CY
- 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
591 CY
- 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
See also
Timelines of Other Worlds & Spaces
Crossovers between the different worlds and spaces within the Prime Material Plane (Realmspace, Krynnspace, etc) allow the comparison of timelines with that of Oerth.
The year 591 CY appears to be equivalent to 1371 Dale Reckoning (DR) from the continent of Faerun on the world of Toril in Realmspace. Assuming the Forgotten Realms adventure “For Duty & Deity” and the Planescape adventure “Tales From the Infinite Staircase” (which were marketed as crossover adventures) both take place in late 1370 DR, and assuming that the adventure Die Vecna Die! (which includes scenes in the Greyhawk, Ravenloft, and Planescape settings) takes place a few months after “Tales From the Infinite Staircase” and “Faction War”, which seems evident from the political situation in Sigil. This is supported by the ”Wizards Three“ series in Dragon Magazine. In Dragon #185, it is stated that the events of the novel “The Parched Sea”, which takes place on Toril, have just recently occurred. "Novel Ideas" in Dragon #196 places “The Parched Sea” in 1360 DR. Dragon #185 also places the meeting described in that article prior to the events of the adventure Vecna Lives! (which happened in 581 CY according to the Greyhawk supplement The Adventure Begins), which suggests that 1360 DR approximately equals 580 CY. (See external link to Forgotten Realms Fandom wiki below)
Bibliography
- Brown, Anne. Player's Guide. Renton, WA: TSR, 1998.
- Gygax, Gary. The World of Greyhawk. Lake Geneva, WI: TSR, 1980.
- -----. 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.
- Mentzer, Frank. Doc's Island. Lake Geneva, WI: TSR Hobbies, 1983.
- Moore, Roger E. Greyhawk: The Adventure Begins. Renton, WA: Wizards of the Coast, 1998. Page 39.
- Reynolds, Sean K. The Scarlet Brotherhood. Renton, WA: TSR, 1999.
- Sargent, Carl. From the Ashes. Lake Geneva, WI: TSR, 1993.
External link
- Common Year on Wikipedia.
- Oerth entry on Forgotten Realms Fandom wiki.
Encyclopedia Greyhawkania Index
The Encyclopedia Greyhawkania Index (EGI) is based on previous work of Jason Zavoda through '08, continued by numerous other fans. The EGI article has a list of sources, product names, abbreviations, and a link to the full, downloadable index.
| Topic | Type | Description | Product | Page/Card/Image |
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