General Head-Canon here, feel free to correct my mistakes.
582 - Planemeld
Aldmeri Dominion/Daggerfall Covenant/Ebonheart Pact Storylines occur simultaneously. (Cadwell's Silver/Gold sends you back in time to experience the ones you didn't originally do.)
Fighter's Guild/Mage's Guild Storylines occur simultaneously
Planemeld (Main Quest)
Craglorn
583 - Planemeld Aftermath
Imperial City
Orsinium
Dark Brotherhood/Thieves Guild storylines occur simultaneously
584 - Daedric War
Shadows of the Hist
Morrowind
Horns of the Reach
Clockwork City
Dragon Bones
Summerset
585 - Season of The Dragon
Wolfhunter
Murkmire
Wrathstone
Elsweyr
Scalebreaker
Dragonhold
586 - Dark Heart of Skyrim
Harrowstorm
Greymoor
Stonethorn
Markarth
587 - Gates of Oblivion
Flames of Ambition
Is that about right, if one were to account for the passage of time, despite ZOS's stubborn insistence against it? Am I missing anything? Is anything out of place?
If not, then can we just adopt this ourselves as a basic timeline, to start from?