Hi,

i have a sheet, this follows the day of the week across the row and a
selection of devices going down the column:

mon tue wed thur
device1 10 11 15 18
device2 20 22 30 32
device3 22 25 26 28

on another sheet i need to work out the difference in time that the device
has been used, so for device1 between monday and tuesday it has been used for
one hour.

for this i have been using the =ABS formula, the problem comes when on some
days the device could be in for repair. if this is the case i would like the
formula to understand the cell content as 0 so as far as the formula is
concerned the cell value is 0 (zero) eventhough its actual value is 'repair'

my problem is, is that i cant sufficiently nest the required logical tests
correctly and it has become very annoying, if anyone could halp it would be
verty much apprieciated.

cheers

The Noob.