Calculating Downtime taking into acount 3 possible shifts of production.

Hello,

I would like to determine downtime in hours between two dates and times. In the attached excel sheet I have where you can enter the date and time down in B5 and date and time up in F5. On the shift hours tab it shows the hours for all three shifts. I would like for H5-J5 on the original tab to have formulas to display hours for each shift the machine has been down for. If anyone can help thanks alot.