Formula to calculate the duration in Hours and minutes of a work

Try this formula

WorkEnd - WorkStart

How to convert this (8:30) to 8,5 ours, so I can get a price for spended time?

@Jan, 

Use a Time Interval field.    Then set that field equal to the end time - start time.... and select the desired format.   POOF. 

What??
If I am gonna entertain in a pub for an example, I usally starts around 22:00 (PM) and play until 01:30 (AM), okay?
The answer is gonna be "-20.5 h", how do you explain that??

@Mconneen

If you use a Date/Time field, Ninox does the math properly.

I have a test DB with a clockIn field and clockOut field that are Date/Time fields. Then I have another formula field that takes clockOut - clockIn and I get the proper time. Now that you are using Date/Time fields you now have to be aware that Ninox, behind the scenes, uses milliseconds.

Then you have to have another field that converts the milliseconds to a meaningful number: number(HoursWorked / 3600000).

Give it a try and let us know how it goes.

Hi

Fred's answer is the correct way to go but if you want to stick to a time field use an if stataement to check if your duration is positive or negative and add 24 to the answer if it's negative. You can see that for your -20.5 above, 24-20.5 gives the correct answer, 3.5..

Doing the same without an if statement can be done with this...

TimeEnd-TimeStart+((sign(TimeEnd-TimeStart)-1)*-12)

Regards John

Hello, if it helps, I managed to create a formula to calculate sleep time. I tell myself that this formula can be applied to many other things related to a difference between 2 moments.

if sign(Awakening - Sleep) - 1 then
    Awakening - Sleep + 86400000
else
    Awakening - Sleep
end + Siesta'

The destination field is a formula field.