Ed was born in the year 1899 in Amestris.
-Ed performs his first alchemy when he’s 6 and Al is 5.
-Winry’s parents are killed when Ed is 8 and Al is 7.
-Trisha dies when Ed is 10 years old. Shortly after the boys meet and get training from Izumi, this includes spending a month on Yok Island. Their training would have lasted less than a year in total even if we’re generous and assume that their mother died when Ed had just turned 10 and they find Izumi mere weeks afterwords.
-They perform human transmutation to bring her back in February when Ed is 11 (right after finishing training with Izumi).
-Also while he’s 11, Ed gets his automail arm and leg. He seems in excellent condition (fighting fit!) in October where he burns down his house and they leave for central. That’s no more than 8 months recovery time from the transmutation.
-Once in central they spend months studying with Tucker and Nina. (Gracia is 5 months pregnant when they’re on the train and Elysia is born on Ed’s 12th birthday so that must be late January/Early Feb, I think the preferred day for Ed’s birthday is the 3rd of February.). That’s a minimum of four months there.
-Some time after this, while Ed’s still 12, Ed takes the State Alchemy exam.
-Alchemy exam is episode 6. Episode 7, 8 and 9 all take place while Ed is 12, before a time skip back to the present (Liore).
-In episodes 1-2 (Liore) and episodes 10-22, Ed is 15 and he turns 16 in episode 23, (Fullmetal Heart) while he’s recovering from the Lab 5 incident. He remains 16 for the rest of the series.
-In Lior, unrest begins seemingly straight after the Elrics leave. It’s bad in episode 13 and in episode 15 while Ed and AL are meeting Marcoh and getting attacked by Scar, Rose is attacked by a group of soldiers. We don’t see her again until episode 40 (the scar) and she now has a very young baby. It’s hard to know how old the baby is but probably at least 10 months has passed between those episodes, perhaps a full year or even more.
-In that time:
-Ed and Al travelled to Risemboolb where Winry repaired his arm in just three days
-They decoded Marcoh’s notes which is suggested to have taken quite a while as it was very difficult. (Perhaps multiple weeks though no exact times are given other than Sheska taking three whole days to write out the notes for them.) Additionally, Scar is shown heavily injured in episode 18 when they arrived but appears recovered by the time they enter Lab 5.
-They entered Lab 5 and received grievous injuries (this is a single night)
-They recovered from those injuries and identities crises. (Again, heavy injuries and automail repair suggests that this would have taken a while, as they are recovered by the time they leave in episode 25, Words of Farewell.)
-They travelled to Rush Valley with Winry.
-Travelled to Dublith alongside Winry, Izumi and Sig. This includes spending at least a night or two on Yok island, perhaps a bit longer (its unclear).
-They meet Wrath and invade Southern HQ
-They meet with Dante and encounter Greed.
-They leave Dublith, staying at least long enough to prepare some graves, and repair Ed’s automail again.
-Travel towards Ishval. This is suggested to take quite a while as they stop off in a small town in episode 35 and seem to be travelling mostly on foot though they may have taken trains and taxis at points.
-Meet a group of Ishvalans in Kishua, and stay there long enough to help out. Winry leaves at this moment, heading to central.
-Travelled to another random town, again on foot. Here they meet Marta who offers them a lift on her bike, taking them the rest of the way to Ishval. They spend at least one night with her.
-Finally, they make it to a military outpost outside Liore. Ed enters Liore shortly after, meeting up with Rose.
—Episode 40–42 are spent within Liore presumably a couple days pass at least as the military seems concerned about how long Ed’s been gone.
-So, episode 43 (the stray), Ed and Al travel by foot away from Lior towards Risembool. When they arrive Hohenheim is there but he only spends the night (in a cave with Al) before leaving to go to central.
-When Hohenheim gets to central, Dante is there with Rose, Sloth, Wrath, Lust (on a wall) and Gluttony. Pride’s also in central and I have no idea where Envy is or what he’s been doing, he was the only homunculus not in Liore and he arrives sometime after Dante defeats Hohenheim. He’s very angry to have missed seeing him. Dante wants Envy to cause some war in the north but he’s too angry and instead Dante just redirects him to attack the Elrics.
-Mustang also leaves Risembool pretty quickly, returning to Central. He confronts Bradley who ends up sending him north to Drachma though Mustang secretly hangs back while Armstrong stages a coup for him.
Meanwhile, Ed and Al leave Risembool in disguise (which work for like 5 minutes…) Ed goes to see izumi at Dante’s house then fights Tucker and Wrath and Sloth in Central. Al gets kidnapped by Envy so Ed goes to confront Dante, running into Mustang on his way to kill Pride. These all seem to happen pretty quickly. This brings us to the end of the series, with Ed sacrificing himself for Al and ending up on the other side of the gate.
-The epilogue takes place around six weeks after with the military being dismantled, it’s a time of change. Mustang is recovering from his very severe injuries. Al is back in Risembool but is leaving again to going train under Izumi. Sheska is back in central, exchanging letters with Winry. Rose is in Risembool, raising her son who is looking noticeably older now.
Now, the Gate messes with timelines completely. Ed goes through the Gate in Episode 49 (the Other side of the Gate) and it’s 1916 in London, where he arrives. This is consistent with Amestris time, (Ed is born in 1899 and he’d be turning 17 in February 1916 so it could very well be early 1916 in Amestris. )
However, Hohenheim seems to have been stuck on the other side for ages given how established he is there, with alter Ed and connections to the UK wartime Government. But it can’t have been long at all if time flowed the same way as he only got into the gate in episode 45, four episodes before Ed where not much time could have passed. When Ed goes through again in Episode 51 it’s now 1921 (5 years gone?) and he’s also in Germany not London though he could’ve appeared in London maybe. He doesn’t appear to be 5 years older but just as long has passed for him as Al so this can only mean that travelling through the gate can seriously mess with time.
In the epilogue, Ed’s probably 16 or just turned 17 in the year 1921. This is why in the (not explicitly canon) OVA, kids it’s suggested that his hundredth Birthday would be in the year 2005.