How To Calculate Time Difference in Open Office Calc

Open Office Calc is free software for creating Spreadsheets. It is capable of making certain calculations very easy to perform. One such calculation is the difference in time between two cells.

One would think that Calc would have a function built for that (it looks like Excel has a timediff function that does this). Unfortunately, after having done some research, I found out it doesn't. So I use an equation for calculating the time difference between two cells. Here's an equation for hours and minutes:

=((HOUR(end time cell)+(MINUTE(end time cell)/60))-(HOUR(start time cell)+(MINUTE(start time cell)/60)))*60

Here's an equation for hours, minutes, and seconds:

=((HOUR(D1033)+(MINUTE(D1033)/60)+(SECOND(D1033)/3600))-(HOUR(C1033)+(MINUTE(C1033)/60)+SECOND(C1033)/3600))*60

There are two things to be aware of regarding this equation:

1. If the start time cell has 11pm and the end time cell has 2am of the following day, you will receive a negative number.

2. If you place this equation in a cell and press the 'enter' key, you'll see the difference. If you want to copy this equation to multiple cells below it you'll need to:

Select the cell that has this equation in it (you will then see a small black box in the lower right corner of the cell)
Place your cursor over this box - the cursor will turn into a + sign.
Press and hold the mouse button while you drag your cursor down to the cells below. As you move your cursor down, you will see a red box appear that shows you what cells this equation will be copied to.
When the cells you want the equation copied to are all in red, release the mouse button. You should now see the cells full of difference values.