Has anyone figured out how to compare two date fields on a single contact?

Use case 1: I'm trying to create a segment/filter that returns contacts who have a datefield1 that is greater/less/equal to datefield2.

Use case 2: I'd like to create a filter that returns contacts where contact.datefield1 is greater/less/equal than linked CDO.datefield1.

I tried some out-of-box stuff.. no luck.. the closest i got was contact.datefield1 dynamically greater than today and contact.datefield2 dynamically less than today…. if both dates are on the same day (but different times) then I don't get my use case :(. I guess it could work for "equal", but that's still not exact time.