I need to find the hours worked by subtracting the time started from the
time finished, time worked may cover more than one day.
ex.
arrived 08:00
depart 17:00

17:00-8:00= 9

Works great until you go past 23:59.
ex.
arrive 21:00
depart 0:30

21:00-0:15= -20:45

So, my question is, what is the correct way to calculate the amount of
time that I spent at the customer's place?

The 2 fields (Departure Time and Arrival Time) that are being subtracted
are time fields and my total hours field is an auto-caculate: Departure
Time-Arrival Time

"Jamie Bah" <jamiebah (AT) hotmail (DOT) com> wrote

(Departure Time - Arrival Time) + ((Departure Time < Arrival Time) * 86400)

I'm assuming you meant 0:30-21:00 = -20:30 otherwise you lost me.

If the total work time can be more than 24 hours you will need an
additional field for days. Then you could do something like :

WorkTime = DepTime - ArrTime + (Time(24:00:00) * days)

If this is not going to happen (which I assume, otherwise you're making
long hours...), do this :

Worktime =

If(DepTime < ArrTime ; DepTime - ArrTime + Time(24;00;00); DepTime -
ArrTime)

or alternatively (same, but differently phrased)

DepTime - ArrTime + ((DepTime < ArrTime) * Time(24;00;00))

You mention WorkTime is an autocalc, which I take to mean an auto-enter
calculation. It's better to just make it a plain calculation field, type
time, so it will automatically update when you change either of the two
time fields. An auto-enter calculation does not update it there's already a
result in the field.

Peter