Calculate number of hours from Start date and time and End date and time

Hi,

What I've done in my office now is create a google form for my employees to fill in their overtime claims. They enter the date and time that they worked. I copy the data from the google spreadsheet onto excel.

I need a formula that will calculate the number of hours from the start time and end time.

An example of what it looks like is :

Cell N2: 29/5/2013 5:30:00 PM ---> start time
Cell O2: /5/2013 8:30:00 PM ---> end time


So for the example above, it should be 3 hours. I also need the formula to work for when it goes over night. For example :

Cell N2: 29/5/2013 10:30:00 PM ---> start time
Cell O2: 30/5/2013 12:30:00 AM ---> End time


I have formatted the start and end cells as d/m/yyyy h:mm


Thanks!

Thanks alot benishiryo!

Your formula and formatting worked!

However, my problem now is, I need to multiply the number of hours with another number to calculate how much they should be paid. This is not working because of the formatting. Do you know how I could resolve this?

What I've tested is for a total overtime of 35 hours but excel is taking it as 1.4583333. I'm guessing thats the number of days.