Into the Underdark

Non Canon Material: The IDW comics and Dragon Age Journeys are non-canon and added for posterity.

Short Stories:

Sebastian: Derived from the timeline outlined for his age. He is 28 as Act 3 of DA2. He was given to the Chantry shortly after receiving his grandfathers bow at the age of 13. Additionally, he states not having returned to Starkhaven for 15 years.

Aveline: Derived from the fact story takes place when she first enters Cailen's army and meets Wesley. Cailen's only been king for 5 years as of DAO, thus giving her the window of 9:25-9:30.

Fenris: Derived from the fact when we recruit him, he's been on the run for 3 years, putting the earliest this story can happen at 9:28. Given that the story doesn't specify where it takes place other than outside Tevinter, it give us the time frame of 9:28-9:30.

Merrill and Varric: Stated to happen before the events of Act 1.

Anders: He has a dedicated window of becoming an abomination post Awakening which means he specifically has a window of Month 7-12 of 9:31 for this to happen.

Isabela: Is stated to arrive in Kirkwall after the Tome of Koslun is stolen. It is noted to be stolen in 9:31.

The Next One: Evka isn't with Antoine at this time. But we know that Antoine joins the Wardens at the earliest in 9:45 due to the short story Hunger, which has the time frame of 9:45 when the Wardens were summoned back to Weisshaupt.

Ruins of Reality: Occurs after the Tevinter Night Anthology of Three Trees Till Midnight.

The Wake: Lucanis states in Veilguard that he's been missing from Treviso for a year and was declared dead. Meaning this has to occur in 9:51.

As We Fly: Lucanis states that the Antaam started occupying Treviso in his absence/"death".

Comics:

The Missing: Is supposed to lead directly into Veilguard. We also know Rook is recruited after these events and Rook has been with Varric and Harding about 6 months prior to the events of Veilguard.

Games:

A Tale of Orzammar: Events happen before DAO. DAO is stated to begin in the first month of 9:30, leaving this to take place in 9:29.

The Last Court: States it is early summer/late spring. Inquisition takes place 1 year after the Mage Templar War is declared, meaning that Inquisition presumable starts in late autumn/early winter when referencing the start of the war in Asunder.