Spreadsheet to schedule a task

I am trying to make a spread sheet that calculates shutdown times for a fan.

I would like it to do this on a rolling 1 month period, and show the last 3-4 shutdowns.

This is what i have so far:-

Start date: 05/04/12 00:00
Run untill: 05/04/12 18:00
Total: 18 hours
Stopped from: 05/04/12 18:00
until: 06/04/12 06:00
Total shutdown: time 12 hours
Run From: 06/04/12 06:00
Untill: 06/04/12 18:00
Total: 12 hours
Stopped from: 06/04/12 18:00
until: 07/04/12 06:00
Total shutdown: time 12 hours

Obviously this equates to about 15 columns for just 2 days worth, so i want the spreadsheet to only show the last 2-3 days shutdowns but the total to still incorporate the hole time period.

Can anyone help?

Thanks

Dan

Forgot to mention, all yellow cells are to be inputted by the user.

Attached is my current sheet, as you can see the sheet currently goes to Cell FX for a month period, I need to monitor the fan shutdowns over a monthly/yearly period.

I do however have to monitor multiple fans, and i would like them on the same spreadsheet.

Thanks

Dan

8 fans,

They will not be shutdown at the same times tho, so 1 fan might be shutdown 15 times a month, the other may be shutdown 10 times a month, but i want each individual fan to show the last 3-4 shutdowns if possible?

Thanks alot!

Dan