Chronology

Here on earth we use B.C. and A.D. to describe time in terms of years based on a fixed point. In Equestria however, they use B.D. (Before Discord) and A.S. (Anno Sororis- the year of our sisters) to do similarly.

The Past
?/?/0000- Discord is defeated

?/?/1010- Princess Luna is banished to the moon

06/21/2010- Princess Luna returns

The Present
July 24th, 2016 - A portal opens in the skies above Canterlot, spitting out a red demoness. She is injured by a night guard with a gun, but is taken to a nearby tavern to heal. A break-in at a local jewelry shop is foiled by Cinderheart, Spectral Song, and a masked hero from Vanhoover.

July 26th, 2016 - Gale posts on the sub, offering to help anypony with pretty much anything in the wake of Kiriai's arrival. Masque offers to meet up with him and grab a coffee, and the two briefly exchange greetings and stuff in front of a coffee shop before heading up to Canterlot, to help Numbers get a box of plot-relevant mysteries onto a train bound for Applewood. Gale and Masque then proceed to flirt for the next couple hours, get Chineighse takeout, and make sweet love at Gale's place.

July 27th, 2016 - Gale and Masque sort of have a falling-out and part ways for the time being. Also Masque's socks are now at Gale's house. All of them. And the cheesekini.

August 2nd, 2016 - An unknown Numbers lookalike posts an ominous video on the subreddit. Quick Fix volunteers to investigate, on the condition that Masque uses his clears some red tape preventing the former from leaving Canterlot. The changeling does so, and Quick proceeds down to Ponyville, to ask Gale about where Numbers had gone. The two then take the train down to Applewood, in search of Numbers. They get led on a magical journey all the way to the Undiscovered West, where stuff happens but I frankly have no idea what.

August 7th, 2016 - Masque posts on the sub, asking if anypony wants to hang out or something along those lines. Basically he's trying to get more activity going on the sub because you can never have enough. Kiriai responds a couple days later, and after hanging out at the Devil's Gate tavern for a short while the two decide to go find a rich young pony to mess with. They eventually find one by the name of New Moon, as he's skulking around (always wanted to say that) in the Taxi Driver-esque depths of Canterlot. They take him back to the Devil's Gate, bringing along another (disguised) changeling by the name of Bass. Sex and blackmail ensues.

August 13th, 2016 - The Canterlot Gazette publishes an article about stuff. Basically they do a short piece on Kiriai, a short thingie on Flow/Blink/whoever and a slightly longer thing on Mixxer. Hilarity ensues except it doesn't, although Masque manages to get involved in it and eventually runs into Bass again. They hang out for a while and Masque spends the night at the abandoned warehouse she calls home, mostly because he re-breaks his leg at some point during all this. Then he goes home.

August 22nd, 2016 - Apparently at some point prior to this Gale (and possibly Quick?) had tracked Letters, the mysterious Numbers lookalike from a couple days ago, to a hospital in Canterlot. Masque briefly heads up to the capital city to try and make amends with Gale, because if there's one thing he doesn't know it's how to be a consistently-written character. Anyhoo, that fails, mostly because Masque nearly chewed the griffon's arm off. Soon after, the changeling heads home, and Gale, seemingly desperate for any help he can get, turns to Kiriai. And promptly signs off on ten years of service to her in the hopes it'll get him closer to Letters.

From then until like November 2016: Tldr, Numbers is shipped with Gale before breaking up with him and fucking Shadow instead, and a bunch of other stuff happens. Also the cast plays DnD, with the exception of Masque who drops out pretty soon after the campaign starts because his author is an incompetent piece of shit. Also I think Bass becomes a New Model Bugpone? Maybe? Not sure tbh.