TIMELINE & DATE:
I think Season 3 happens during 2021 with the last few episodes happening after Homelander's Birthday Special which is July 4th. So I put the action for the last few episodes to happen towards the end of August or first week of September.
For this story I am moving the date up by one year so Chapters 1 through 35 happen during the last week of August first week of September 2022.
My reasoning is that in the show they have a presidential election coming up. In the real world the next election is 2024 and campaigning starts around two years before the election so it fits nicely with the real world and makes future date calculations much easier for me.
As I'm starting the time skip I won't be providing exact dates only months and years and sometimes only years as we get further along the timeline.