I am back with more useless questions! Please forgive me!
I tried to look in the A Guide to Sigil sourcebook for notes on the passage of time.
It says that the days are divided into antipeak, peak etc, but it doesnt mention a calendar system, what do you use in your campaign? Right now I am suing Greyhawk's (the player's home world) butr is it possible that Sigil doesnt have any? Has anyone made a timeline of Sigil events (besides the great upheaval and the faction war). How do Guvners and Fated (pre-FW) mark time on documents? I think there must be some sort of standard... damn there are really a LOT of obscure points in this campaign world, compared to the other ones.. (well I guess it's intentional in a way, but it seems so dispresive at times)
Calendar
The most common datekeeping system in Sigil is 'Guvner Administration', counting years since the elevation to leadership of the current Guvner factol. 'Present day' for the original Planescape boxed set was 127th Year of Factol Hashkar's Administration, IIRC. Since the Faction War kicked over the applecart, dates have used that as a reference point - so 'Present day' for Planewalker sigil is Year 5 PFW.
(And yes, a year is 365ish days, just to keep things simple. The Guvners, Signers and Godsmen all looked at all the different Prime worlds that shared a 365 day year, declared a year of that length to be Blessed by the Powers, and nobody's since dared to argue with them. Well, the Athar tried, but they soon discovered that changing planetary orbits just to prove a point was beyond even their limits...)
Most of us use Ken Lipka's Philosophical Calendar, where each month is based on a faction and the days are named after wards. Because it's awesome.
Did anyone ever create a full(er) list of Feast Days or other major celebrations and holidays in the Cage? It's exactly the kind of local color I think Sigil is missing, possibly because I don't know where to look.
I don't recall if anyone did - but if someone were to... it'd be *quite* nice to have it pop up as an article for us. 
Opps sorry, found it: "a real calendar doesn't exist and traditionally the year is referred to the reign of the Guvners factol (for example: 127° year of factol Hashkar's reign)"
Anyway, if someone has a calendar of events please let me know!