Overall, Big Hero 6 starts in 2032. Sometime around March-April (the concept art book shows a March calendar + if you look REALLY closely at Yokai's newspaper wall, there's a newspaper for the Krei Tech Building opening dated 'Friday March' with the day and year being hidden. Plus this frame from the IDW BH6 the Series comics backs up the 2032 date
And it seems that the IDW comics fall between Killer App (poor NBB being a villain) and Fan Friction (per Go Go's lines about not being outskated/outran). Overall season 1 runs from around March-April to mid November 2032. But today we're not talking about that, today I'm talking about something no one has pointed out.
Internabout starts on November 17th 2032 (per calendar, day given and Obake Yashiki putting us in November). Also between there and Countdown is Steamer's Revenge and Big Hero 7 actually per Wasabi's car. That's one of the only parts of production order that lines up. This puts Steamer's Revenge on November 4-8th I think per Wasabi's birthday being on a Saturday (with calendar in ep matching Nov 2032 calendar irl), with Big Hero 7 occurring between there and Countdown. Anywho, Something's Fishy is said to occur on a Saturday, and there is GOOD reason for it to be about a week after Internabout.
In July of 2033 (in Big Chibi 6), Karmi said "During my last few weeks at SFIT" when talking about getting an interest in robotics. If we take that literally, that means that Season 2A only lasted a few weeks. Let me repeat that. A FEW WEEKS?!
There has to be at least 10 or so days to account all episodes after COM up to The Present. Then it's basically a timejump to Late May/probaly Early June 2033 per the only truth in Krei's employee of the month wall in "Hiro the Villain". A few weeks can be 3-4, which if we're counting from Nov. 17, and using 3 or 3.5 for the bare minimum, that means City of Monsters ended around December 8th-11th 2032. All of THAT happened within A FEW WEEKS!! Big Hero 6's tenure as fugitives lasted around 6 months, but San Fransokyo, Hiro, and Karmi suffered all that pain WITHIN 3ISH WEEKS!!
Big Problem would occur around late September 2032 btw per Big Problem. Anywho, some more quick timeline notes before I leave.
1; the only explicit date we get in season 1 besides Obake Yashiki and Steamer's Revenge. Well this is a stretch but still. In Fan Friction, before the jump to morning there's a blue moon. In 2032 that falls on August 21st 2032. This would mean that the episode occurs around Aug. 19-22 2032. (Failure Mode might occur in mid April per the project possibly aligning with the anniversary of the Great Catastrophe. Also we're in Spring until Mr. Sparklez Loses His Sparkle at least per Wasabi's allergies)
(screenshot from YouTube Big Chibi 6 clip by DisneyXD btw)
2; In "The MiSFIT", it's stated to be midsummer, which would be mid July. However while this calendar in Big Chibi 6 does align with August 2032, that's near the end of summer. Due to timeline sake, it was probaly intended to be and will be considered July 2033. Season 3 more or less takes place over 2ish months; meanwhile Season 2 overall occurs over the span of roughly 7 months. Baymax! timeline is a bit vague, although March 30th-April 4th can be found using Kiko's medicine holder, calendars and dates in episode 3, and Hiro's statement in episode 6. I choose 2033 because
1; Lack of Big Hero 6 despite them being quite busy in 2032. This can be explained by them laying low due to Chief Cruz.
2; Cass has a different cappuccino machine, which could be switchable with her steam one since the cafe's doing so well.
3; Sofia's seasonal allergies are mentioned, which would fall in line with the springtime clues.
4; The calendars match up to 2033, and while they COULD for 2032 depending, 2033 works overall.
Anywho that's about it. For Baymax Dreams and the Baymax & shorts you just watch them per when episodes came out per their release dates. Although I would save all or at least the last two of the last half of the Dreams episodes for after Big Chibi 6 so it makes sense Hardlight would appear as a memory, and Dreams starts after Countdown per Obake Baymax confirmed by subtitles in ep 1.
Anywho, that's all for now. Hope yall enjoyed the timeline info.
(P.S, overall the images shown are from the BH6 wiki BTW)