Easy Calendar Techniques
One of the things stressed in the original game of D8D was the importance
of recording game time with respect to each and every player character in
a campaign. In AD&D it is emphasized even more: YOU CAN NOT HAVE A
MEANINGFUL CAMPAIGN IF STRICT TIME RECORDS ARE NOT KEPT.
--Gary Gygax, Dungeon Master's Guide
One of my recommendations for better game mastering techniques was to keep a calendar. It seems really mundane, but it's a simple document for structuring information that yields significant benefits. One of the challenges of the DM is Information Architecture; how do you structure the information at the table to easily track NPCs, the setting, adventure details, important PC notes, etc? It must combine long term storage with ease of use at the table. We have sandbox structures, one-page adventures, NPC index cards, word documents, wikis, paper notebooks. A printed calendar is another simple tool.
For each campaign world year, I build a calendar for the entire year in a spreadsheet - a row for each day. Next step is to calculate weather for each day of the year; I use the probable home base or general sandbox location for the locus. There's an excellent article in Dragon 137 (Weathering the Storms) that provides simple formulae and weather patterns for a range of climates based on terrain and latitude. I find they're detailed enough for fantasy gaming and the formulas are easy to plug into Excel for calculating daily weather month by month - they provide temperature, precipitation, and wind.
Next up, I bust out the D&D Rules Cyclopedia to generate the chance for various annual Domain events (and then randomize the month and day for the occurrence). The domain tables provide a mix of natural events and intrigue; they were originally printed in the D&D Companion book.
You end up with a schedule of weather and events for the sandbox area for the next calendar year, and a handy tool for marking the passage of time. Will it take 3 weeks to copy that scroll back in town? Then you know it will be day X and month Y when adventuring resumes; you'll be able to quickly describe the weather and set the tone. The calendar is a handy tool for marking key notes right on the print out - here is the day so-and-so died, this is when we started the new delve, etc. The ongoing benefits are excellent.
The standard Greyhawk calendar has some built-in holidays and feast weeks; I add some local holidays to the mix as well; for instance, the King of Keoland requires that all the vassal states like Sterich celebrate the founding of Keoland.
The last thing I do as we roll into a new calendar year is have the players advance their character ages one year. I'm not interested in tracking individual birthdays for disposable PCs, so advancing everyone's character age at the same time is simple. Since Gothic Greyhawk is using LL and the Advanced Edition Companion these days, we're using the AD&D 1E age tables via the AEC.
Here's a quick snapshot from the current spreadsheet; the campaign recently crossed into year cy577 in Greyhawk terms, so it's basically January. Sterich is around the 35° latitutde area, giving it a warm climate with dry winters; January (Fireseek) is the wettest winter month. A good rule of thumb is to drop the temperature 5° every 1,000 feet for altitude, so Barovia (at 8,000 feet - similar to Nederland in my old home area of Boulder, Co) is closer to 10° and snowing when the calendar indicates 40° and rain for the lowlands.
Once you've got the spreadsheet formulas built, it's simple to generate a new year's worth of weather and events. My calendars see heavy use in the ongoing campaign; like a good map, I get significantly more out of it than what I put in.