This is a version of https://github.com/TheIttim/Move-or-Delete-Files-based-on-LastMod refined for what I needed. This script will archive anything in the set src path not modified in over a month, in this case, downloads, and put it in the dst path, in this case Archive, then check the dst and delete anything not modified in 2 months.
Task Scheduler can be used to set this script to run whenever you want. I personally have it set to automatically run at 12:00:00AM on the 1st & 15th of Every Month.