Addresses [MJ-957], [MJ-955], and [MJ-951]

Went with a minimalistic approach this time in an effort to avoid regressions. This addresses the off by one error observed in the PRM date widget, the AttributeError observed by clicking "View All" in the same widget, and the record filter regression caused by my previous attempts. 

Depending on how long this takes to review/merge, I'll probably do refactoring in a different PR to reduce code duplication.
The or here will treat a None as False, which is why we don't have to trap this in try/except.