I guess in your case you're never doing date arithmetic or greater than or less than, but only doing equality testing, right? That is, it's part of a composite key.

I faced a similar problem with a form where people were supposed to submit a date and probably not aware of what timezone was involved. I figured that so long as they selected "02/28/1993" and people always saw "02/28/1993" that was correct and if they ever saw it differently it was wrong. So I used non-TZ aware dates throughout the whole system.