access-need to get hours worked from start to end minus 30 min

[Guest]

trying to come up with a formula that will return this total. I get the
total hours worked with the 30 minutes included. Can't find a way to
subtract the 30 min. Help

 

[Allen Browne]

Try:
Hours: (DateDiff("n", [StartTime], [EndTime]) - 30) / 60

For more detail, see:
Calculating elapsed time
at:
http://allenbrowne.com/casu-13.html

 

[Allan Murphy]

How is the total hours displayed as 12.50 meaning 12 hours 30 mins or 12:30?