I'm back, baby!!

So how long did the original Yugioh take place in universe? I know someone on here did some of the math for the duel monsters anime and concluded it all took place in around a month, which is possible for most of the arcs since most the runtime is just card games...

But in the manga it's stated they're all first years in high school when everything starts, and the ceremonial duel takes place six months before graduation, so third year. I'm also pretty sure there's a scene mentioning them moving on to their second year at some point in the manga before duelist kingdom.

I assume that the graduation takes place in march-april since that's usually when school years end and begin in Japan, so that's around October-November when the ceremonial duel happens?

If only we knew when the series started aside from the year we might be able to make a timeline of events...

If anyone wants to throw in things I missed or correct me go right ahead.

at one point i had mapped out nearly every chapter on a timeline from at least the first 7 volumes of the manga, so I can’t actually pinpoint how long it took to get to the millennium arc but i can tell you at least this:

• the series proper starts approximately April 1996 (year is a guesstimate based on the fact that it came out irl in the 90s and it was clearly meant to emulate modern day)
• every chapter up to the part where Mokuba first appears takes place over one extremely wild two months, which we know for sure because at this point, characters start wearing their summer uniforms, and then a few chapters explicitly happen over summer break. I believe there’s also an indication somewhere (I think after Jonouchi faces his old gang? sorry my notes are old) that there’s a couple of weeks to a month in between one chapter and another
• Duelist Kingdom takes place over like, a single weekend which I calculated as somewhere in March 1997, so at this point yea nearly a year has passed
• We know for sure that a year has passed just after Duelist Kingdom because in the manga, the cast mentions that they’ve started a new year of school, and Hanasaki (Zombyre kid) ended up in a different class from the main gang (to never be seen or mentioned again). So Duelist Kingdom happens approximately just before April 1997.

This is unfortunately where my notes stop but if I remember correctly in the anime continuity at least, Battle City happens pretty soon after Duelist Kingdom, so I can’t imagine it was more than a few weeks or so afterward, maybe a month at the most. Battle City only lasts a couple of days in universe, and then I can’t quite remember all that led up to the millennium world arc. 

Still, I think it’s quite possible to infer that there was some downtime before and after Battle City that would have allowed for them to wait until 6mo pre-graduation to have the Ceremonial Duel, since at the very least we do know that they are second years during Battle City, and Japanese high school is only three years, so there’s just a handful of months to account for.

Idk if this helped at all and i’m sorry i can’t point you to specific parts of the manga to cite my sources, all i have is this stupidly detailed timeline i made like seven years ago and i didn’t note where i’d pulled dates/time spans from.

it should also be noted that Takahashi notoriously doesn’t really remember his own series all that well, so time could absolutely be fudged