You can easily calculate the seconds between two dates and times in excel. All you have to do is enter the following into the formula bar
=((finish_date+finish_time)-(start_date+start_time))2460*60
Example
Below is a worked example for how to calculate the seconds between two dates and times in excel
Here you can see
=((finish_date+finish_time)-(start_date+start_time))2460*60
becomes
=((C3+D3)-(A3+B3))2460*60
Typo in the formula. I think you want *24*60*60, not *2460*60
What he said 🙂