The latest releast 2.3-dr7 displays time incorrectly when using the {date-data} macro in this format:
{date-data:x|format=hh:mma}{date-data}.
In edit mode, if you set the time to 02:03 AM, in view/preview mode it shows 01:59 am.
Have attached screenshots.
The problem was that when no year value was being supplied, the year '0' (which technically, does not even exist) was being used instead. This was compiling, but was introducing the noted error.
Choosing which year is appropriate for non-specified values is a little tricky, but 2000 was decided on. It is recent enough to be reliable, is a nice round number, and will be consistent. An alternative considered was the current year, but this would cause problems when sorting by the date, since newer values may be set to a different year, which would alter the sort order when it is intended to sort by the time.