> Just to make it shorter: make an additional field in the data,
> containing just hours (decimal hours, with 5 hours 45 minutes expressed
> as 5.75) or hours:minutes in two fields, so you calculate that only
> once.
There are 1440 minutes in 24 hours, so you could store the number of
minutes in a 4 character slot, and then do the conversion to hh:mm on
the fly. This also makes arithmetic easier when comparing or
calculating times.
/Paul