Backup weekly current production db to Historical db server I have a production sql db of 600gb and a historical server where i move the full db every month.
Now we want to have only the last 3 months information on the production server, and move every week data from the production DB to historical server, to then delete each register which have more than 90 days old.

I couldnt find the best way to do that. 
Should i save the date of each register i put on the database to know when it was stored? 
Does sql server have any function to know when a register was stored?

Both database are stored on AWS, so it´s easy to move data between them.
Thanks a lot!
You can look into replication as well (not sure if it works on AWS though)

[Prod SQL] --> [Archive SQL] constantly

periodically delete on Prod: anything > 90 days
periodically delete on Archive: anything > 365 days maybe?

If not replication, does "linked server" work on AWS?

Not sure what you mean by "register"