The Answer To A Question No Body Asked Part 2 -Episode Order June

It's my understanding that Hasbro has said that the first 3 seasons were 1 year.
Even allowing  for 90 days of Winter with no adventures this is mathematically possible. 
Since the show starts "2 days until the Summer Sun Celebration"
I'm going to run the calendar from June to June

It helps if  you assume that most of the Crusader episodes take place during other episodes.

It also helps A LOT if you assume that Magical Mystery Cure took place over 1 day. 
This means that Fluttershy gave up very quickly
& that the dilapidation of the Apple farm & the boutique were exaggerated for dramatic effect. 

In EQ, Winter has to come & go like snapping a light switch
One day, you've got 2 feet of snow & you're ice skating.
Literally the next day, it's picnic & swimming weather.
In EQ, magic works. If there is no ceremony, the season's don't change
(But that's another thread)

The episodes' artwork isn't completely accurate & can't be used to date episodes
Almost none of the episodes show trees with no leaves or Autumn colored leaves
All the episodes showing Apple trees show the trees with ripe apples.
These things aren't possible. They also show different colored apples
on the same tree. That is possible.
Apple trees often have branches from other trees grafted on to them.
(IRL, you usually try to have them all ripen about the same time
IMO, the Apples have it spread out so they can handle the harvest themselves
+ different apples are better for different things)

Surprisingly, crops are going to date several episodes,
so I looked it up on Wikipedia. They say apple harvest (USA) varies by type
Starting mid July, running to late October.
Cherries vary -the colder the later
But northern hemisphere, May into September

The time covered by the seasons.
The first 3 seasons cover the first year.
If you accept the Equestria girls movies as canon, the first movie has to be
between Magical Mystery Cure and Princess Twilight
because Twilight is an alicorn & still has the "big crowny thing"

The calendar says otherwise, but in the USA Summer is considered to run from
Memorial Day (last weekend in May) to Labor Day (first weekend in Sept)
All of June is considered Summer, all of September is considered Autumn
(surprisingly, this helps date some episodes)

Events in the Cutie Mark Chronicles
School is out because
The usual time to apply for school is between semesters
Pinkie & AJ aren't in school
Dash & Fluttershy are in Junior Flight Camp (IMO, this is like Summer Camp)
Rarity is in a play, but some schools do stuff like this over Summer, or it could be Community Theater
This means that Spike's birthday (Secret of My Excess) is late May to late July.

Year 2
Season 4, Twilight is an alicorn but still lives in the library.
This means that all S4 episodes have to take place between
Princess Twilight & Twilight's Kingdom.

June 19-21 or 22, Year 2
Princess Twilight 2-3 days (Time is messed up, it's hard to say)
"2 days to the Summer Sun Festival", 1 year to the day after the pilot

Season 5, Scare Master is Nightmare Night (Oct 31, year 2)
The season premiere, then (probably) Castle, Sweet Castle
Twilight's Kingdom must be over no later than the 3rd week of October (15-21, year 2)
Pinkie Pride, Dash's birthday must be during S4. This is partially confirmed
because in Super Speedy ....6,000 Dash complains that Pinkie "always" gets all the cider.
This means that both Dash & Pinkie must have been in town at least year by then.

BP = Before the Pilot 
15-25 years BP
Mane 6 are born. (I've got reasons, but that's another blog)
12 years BP
Cutie Mark Crusaders born
AJ's parents are missing in The Cutie Mark Chronicles,
so Bloom must have already been born. I assume that they are all about the same age
11 years BP
The first Rainboom, as shown in The Cutie Mark Chronicles
AJ mostly grew up in Ponyville, Rarity probably did. They did NOT get on well together (Look Before You Sleep)

At some point BP, Fluttershy & Pinkie move to town & become friends with Rarity. 
Head canon, Rarity met Fluttershy through her cat (sick, needed grooming, adopted from, whatever)
Green Isn't Your Color, they are good enough friends that they have a regular spa day
Some time BP.
Putting Your Hoof Down
Fluttershy writes the letter, so that is after Lesson Zero. However, for time considerations I'm going with "that's a flashback episode". There is some evidence Rarity and Fluttershy were friends before the pilot
1 year BP
Dash moves to Ponyville (S4 Pinkie Pride) during that year,
Dash moves to Ponyville on her birthday but Pinkie has to be told this. 
Dash & Pinkie don't get on well together (Griffon the Brush Off) 
YEAR 1
Late  May/ Late July
Either Sweetie or (more likely) Scootaloo moves to town after school lets out
IMO, the timing on several episodes implies that school is early August to early May
The Crusaders have a cameo in the pilot.  I've heard that this is a continuity error,
& that they don't meet until Call of the Cutie (early August).
This means that they weren't in class together BP. 
So, either 1 moved to town (my choice),
they were 6 & just starting school,
or Ponyville has more than 1 class per grade
JUNE
June 19-21/22
Friendship Is Magic 2-3 days (S1 E1 & E2)
The Pilot. I'm assuming the Summer Sun Celebration is June 21 (IRL, the summer solstice, longest day of the year)
This episode is either 2 or 3 days, depending on
"How long did it take to get out to the castle & beat Nightmare Moon?" 
June 23-24
Griffon the Brush Off.  2 days  (S1 E5)
The start of the friendship between Dash & Pinkie.
This or Bridle Gossip is almost certainly their first adventure.
Fluttershy knows Pinkie well enough to say "I'm a year older than you",
which implies that they knew each other BP Letter
June 25-26
Bridle Gossip.  2 days (S1 E9)
Zecora comes to town every month.  This means that it is before the end of July at the very latest.
Twilight has never heard  heard of her. This means that no one came to her
"We're being terrorized by an evil enchantress. Help us, Obi-wan Twilight! You're our only hope!" 
This means that she has little if any street cred as a mage. 
So, it must be before Boast Busters. I'm putting it after Griffin the Brush Off because Dash & Pinkie are hiding together
& this implies that their friendship has started Letter
June 27
Boast Busters 1 day (S1 E6)
It has to be an early episode because no one except Spike urges Twilight to face Trixie.
I'm putting it here because Magic Duel implies it was a long time before that. Letter
June 28
Feeling Pinkie Keen.  1 day (?) (S1 E15)
Assuming the "hydra in the swamp thing" was the same day that "Derpy dumped all that stuff on Twilight"
Has to be an early episode, but after Bridle Gossip
(T doesn't yet believe in curses then & scorns the book Super Naturals)
(Could be in July, but it fits here)
Probably before Sonic Rainboom because Dash is practicing stunts but doesn't do Rainboom Letter
June 30-July 1
Look Before You Sleep. 2 days (S1 E8)
Start of friendship between AJ & Rarity, so it has to be early. 
AJ says that a storm scheduled last week was canceled.
IMO, June 22 was for cleanup after the Summer Sun Celebration,
the storm was supposed to be June 23, but NMM messed things up. Probably June 30-July 1.
Letter. So, Twilight starts July fully up to date on her Friendship Letters
July, Year 1
Unlike June & August, I haven't worked out a tight timeline for July (yet)
I'm using it as sort of a dumping ground for stuff that probably took place
early but not in June or August, so I'll post it later