Hope this helps to clear things up :) I'll be updating this with every chapter of the main story
Timeline
Part 1- How to (Accidentally) Befriend Teenage Wizards: A Guide by an Undercover Archangel
June 1977
Gabriel meets the Marauders, spends the summer with them, leaves in August
Part 2- A Hunter and a Metamorphmagus Walk Into a Dungeon
June 18, 1996
Sirius falls through the Veil, is now stuck as a dog (mentioned mostly)
April 2010
Gabriel 'dies' begins coma-nap in Potter Manor
Feb 21 2016
Teddy leaves on mission to investigate hearts getting ripped out on full moon
Feb 22, 2016
Teddy is captured by the MoL
(Full Moon)
Feb 28, 2016
Harry and Ron discover that Teddy is missing
Mar 3, 2016
Harry tells family
Jamie talks to Marauders and recruits Portraits
Mar 4, 2016
Chuck and Amara leave
Mary is resurrected
Sam is captured by MoL
Cas is banished to Manitoba
Gabe stops dreaming real events
Mar 6, 2016
Dom talks to Luna
Mar 7, 2016
Dean, Mary, and Cas arrive at bunker, discover Sam's abduction
Sam and Sirius arrive at MoL compound
Sam, Sirius, and Teddy escape
Dom sets up a stakeout.
Mar 8, 2016
(2-3 a.m.) Dom confronts Jamie
Dom and Jamie recruit Ghosts and Houselves
Sam and Teddy talk
Greyback shows up, injures Teddy, is driven off
Mar 10, 2016
Dean, Cas, Mary arrive in Britain
Sam, Teddy, and Sirius reach Potter Manor, Sam and Sirius talk
Mar 11, 2016
Dean and Harry's groups reach MoL compound, meet each other and Ketch, find out about Sirius (late at night-early hrs. Morning on the 12th)
Gabriel wakes up, talks to Sirius, Sam and Sirius talk, Gabriel and Sam talk
Mar 12, 2016
Ron goes to Hogwarts to check in with the kids and talk to Headmistress McGonnagal, then goes to see Narcissa Malfoy
Harry, Cas, and Hermione investigate the Veil of Death
They regroup and discuss next steps