fixing datetime exposure in unit tests

 * dates don't inherently encapsulate a timezone, so calculating one was
   resulting in unit test failures during the time that local TZ and UTC
   was out of whack. Resolved by storing "Date" only fields as ordinals
   and loading from the same.
 * also updated unit tests for verifying date-now by using date.today()
   when setting values rather than a datetime, which could be off by
   timezone when compared to date.today()