A little more quick testing showed that the values being persisted by
the Time/Timestamp edits are NOT correct.  They're being munged in some
way, either by my various conversion functions or by something else.  More
digging will be required.  It's even possible I've encountered a core code
bug, but as far as I can recall I had *tested* that values are properly
persisted by the code, so I don't *think* that's the cause of the problem.
I'm pretty sure it's isolated to the way I'm constructing the Calendar
values from the Dates in the edits.  The TZ types I'm not worried about yet --
I know those need work.  But I at least need basic Date/Time/Timestamp
working.