Are there any rules what happen when the Grand Tribunal falls on the same year as a local Tribunal?
If I didn't messed up with my calculations this happens to the Rhine Tribunal in 1228 but other tribunals will have this problem also at some point.
My memory tells me that the local Tribunal is moved one year earlier (1227) to compensate. Don't remember where I read that though.
GotF p.143 has it - but I would expect to find it in other Tribunal books, too.
Cheers
A nice didn't have a look at this time table so fare 
and thanks for the fast answears
I seem to remember that all local tribunals are "synchronized" by some Grand Tribunal ruling early in the Order's history, so when grand and local tribunal coincide in the Rhine they do so everywhere. Thus, it seems likely that the one-year shift takes place everywhere. Incidentally, this is an extremely rare event that happens only once every 231 years (so it took place only once before, in 997).
That's acutally something I find slightly irking in the base setting.
The first tribunal being in 1221 means that a standard saga is going to encounter their first tribunal very quickly. This can be a bit daunting for a novice SG, and on top of that will likely be forgotten. Us old hands know, but less so the newbies.
The next tribunal being in 1227 rather than 1228 is further annoying, because while it is a super rare occurence, it is a rules 'break' from the tradition and it's the first cycle new players see. It sets a bad precedent for those new players, who have only just been told 'its every seven years... except its six'.
This, to me, would be something to address in a 'my first Ars Magica' guide. Unfortunately it would make a poor Sub Rosa article because by the time people get to reading fanzines they're probably not fresh new players to the system.
My preference is to start a saga in 1221 with the new magi Gauntlet in sync with their first Tribunal, and to push back the offical GT dates by a year. So first GT is in 1229, and it goes from there. Obviously a house lore-change, but it makes easing in new players a bit easier.
I agree that it is kind of confusing at first for a new GM and so starting earlyer then 1221 as suggested would be good for a new GM especial when he also have new player who didn't read trough all the lore in the different books as he then can also use this lore for the adventures.
Ah, I found it: it's in the LatL timeline. By Grand Tribunal ruling of 832, Grand Tribunals take place once every 33 years, and Local Tribunals take place once every 7 years starting in 836. Apparently both in 1228 and in 997 the Local Tribunal meetings where pushed back a year to accomodate the Grand Tribunal meeting, exacerbating the problem presented by Kid Gloves: first a six year gap, and then an eight year gap to make up for the lost year.
I'd note that if Grand Tribunals were set to take place once every 35 years, instead of every 33, the problem would never occur!
...except in Transylvania, where they hold Emergency Tribunals every year.
Where is the difficulty of starting a saga in 1217? Or 1204? Or any time period?
I think IMO there is a HUGE benefit to starting games years before the 1220 default. Hell I always try to argue that each character should have a single session game that the PC runs as storyguide. They play their character as a child, then apprentice, and then gauntlet (if they make it that far); even game a scene after gauntlet if you want. And I think each player should run just the one session so they can display who their character is, the stories that are important to the player, and generally get a feel for the character.
I know I am often alone in this however..... 
Where is the harm in missing a Tribunal? If they start in 1220, and in their story they say... "Oh and Tribunal happened, BTW we now all have to wear the color green on months that have a 5th Saturday."
No difficulty unless you move the setting several centuries.
After all, default year use to be 1197 - with the next tribunal in 1200.
If you move too far into the past, parts of A&A become irrelevant, because there are no universities and because Aristotle isn't quite as re-discovered.
Also possibly, some magical tricks aren't invented yet, or are less effective. And ofcourse Alchemy is unknown (as such) in europe before 1144.
If you move forward, you may have to deal with gunpowder and the renaissance in general, but with longevity rituals, that problem might well crop up anyway.
In short, nothng major.
The difficulty in starting it in any time period, according to Mr Chart's address to the UK Grand Tribunal, is Europe's population explosion followed by massive crash and social upheaval from the Black Death. If plague is averted by Hermetic magi, then you have a massively overpopulated Europe at risk of imminent famine and chopping down all the trees. If it isn't averted, you lose vast amounts of population and many urban populations, and you get the social order in many areas turned over due to the shift, so either way Mythic Europe post 1340s will look very different to the 12th/13th century version. Incidentally, a friend of mine has set an Ars game in 17th century Hertfordshire, because it became so depopulated the 1620 population is about the same as the 1220 population.
My current tabletop saga started in 1160, because I wanted magi in place before dealing with events in 1190, and CJ23 wanted to do the battle of Fornham in 1173, so we ripped through 1160-1190 in 6 months, and have spent three years since going from 1190 to 1218.
As for the harm in missing Tribunal - spring covenants can miss tribunal all they like, as they have no political power you can have more fun telling stories where they will be the main power involved. In the early years of a magus' life, Tribunal is mostly a place to do some trading or a place to answer for your indiscretions.
It is no problem. It is just a matter of synchronising with the real history of Europe and the fictitious history of the Order (if your troupe cares).
If you go too far back, the main problem I see is that you realistically start crashing into many more characters who lived through the Schism War (or earlier Order history depending on when you move to). So, you may need to have firmer ideas about what happened. For characters who are interested in such things, it is quite different if the Schism War is the immediate past rather than semi-legendary history (and even more different if it is present or the future!).
If you go too far forward, real Europe undergoes changes, and interacts more with the rest of the world. If this happens in your version of Mythic Europe too, this might mean that the Order of Hermes has to become quite different.
I can't see any problems with moving the start date around a few decades. Only, (if it matters to your saga) you may need to check details like who the pope is, who the king is, where Crusaders might be, which religious Orders exist, who occupies Jerusalem, etc.
Also, if it really matters to you, you can just change the date for Tribunals.
It is only a very slight irk.
I've tended to start sagas in 1221 myself, and in the long-running saga I'm playing in both regular and grand tribunals are not aligned with the official lore. It has no impact on most sagas, I'm sure. As mentioned, its purely because of the newbie-confusion that I've witnessed a couple of times. Most troupes get over it fast enough.
I guess the silver lining is it gets people coming to these forums asking about the lore. If this was intentional, I salute your cunning Mr. Chart.