Side Note on Time Scales and Canon Compatibility · 4:50am May 29th, 2015
I would think this would be somewhat self-evident, but in case it needs further clarification. Heart of Loyalty is diverges from the end of season 3, with Cadence's letter to Celestia happening right before Celestia was about to mail of Starswirl's journal and kick off MMC. Then Tomorrow Came and Heart of Loyalty treat seasons 1 and 2 as occuring over roughly a year each, with season 3 being somewhat less than a year. This will continue to be the case despite the patently nonsensical attempt by the writers to now try and cram all three seasons into a single year. The bit about Luna and the Summer Sun Celebration in season 4 was easy to brush off, but Tanks for the Memories makes a huge mess of it. I won't go into all the details of shoving hearth's warming eve back in with winter wrap up, there only being 52 weeks in a regular year and the problem of a friendship report = 1 week at the minimum, where Lesson Zero is supposed to fit in, how many different apple seasons there are, and the problem of all those wonderful bits of continuity nods and character growth being flipped into negative continuity. I really don't have the time or energy right now.
Suffice it to say, the 1season ~= 1 year time scale is still in effect, and I wait for someone on the writing staff to either give a mind blowing justification or explain what they were all smoking that day when the question inevitably comes up in the next interview panel.