This may be a silly question, but how do I find out what posts I've used for AC in the past? I've been kinda running on autopilot a lot and am only now going through my threads to possibly get items from the traders, but I have absolutely no clue what threads I have and haven't used for AC? I also don't know if threads that got AC-length count for the traders if said length happened over the course of multiple months.

Thank you for your time!