My players are currently working their way through WC in the Greyhawk setting. When the campaign started I thought to use the greyhawk calender (http://www.modeemi.cs.tut.fi/~fey/DD3/calendar_GH.html) to highten the atmosphere. This had some nice roleplaying concequences for especially the religious characters. The players chose a date to start (25th of readying) and are using the calendar to keep a log.
The fortunate coincidence was that they found the empty graves of the Lands family on the 10th of Coldeven. Looking at the calender at the start of the session they asked what the Bloodmoon festival was (11th of coldeven), I told them:
11th= Festival of the Blood-Moon. Sacred to worshippers of Nerull and most lawful evil cults as well, this grim festival technically begins on the 10th and ends on the evening of the 12th. It commemorates the blood-red moon which appeared all over the Flanaess on this day in 294 CY. (Some sages postulated common volcanism as the source, but proponents dwindled quickly after several sages disappeared under mysterious circumstances.) Elaborate ceremonies are held in fell and shadowy places, many of which are grisly and unpleasant in the extreme. This festival is now honoured in Iuz' lands as well since the Wars, in mocking celebration of the surprise attacks which decimated the Heirarchs of Molag in 583 CY.
The players immediately linked the graverobbing to the festival and were even more determined to find the bodies of the Land family than before.
The unfortunate part of the coincidence was that they tried to tackle Filge the same day they fought the owlbear (luckily they were able to bribe the Cullen's gang rather than fight them). Needless to say they were a bit unprepared and almost without (healing!!)spells. This and some bad luck and bad tactical moves almost caused a TPK, luckily they only lost one (see obituary thread) but had to leave his body.
The good thing is that the rest of the party is now very motivated to defeat Filge. The bad thing is that Filge is now ready and will sick the Cullen's gang on them (with a very small chance that they can be bribed again).
I love it! Must integrate this into my run at the AoW! Muwahahaha!