Clarify that uncertainty calculation, just like date/time comparison calculations, considered Seconds and Milliseconds as a single combined precision with Decimal semantics.
 
In addition, clarify that uncertainty is always represented with the lowest boundary first, just like intervals.
 
So, this:
hours between @2017-03-11T01:00:00 and @2017-03-11T02:00:00
Results in 1
As does this:
hours between @2017-03-11T01:00:00 and @2017-03-11T02:00:00.0
But this (specified to minutes on the left and seconds on the right):
hours between @2017-03-11T01:00 and @2017-03-11T02:00:00
Does result in an Uncertainty(0, 1)