How to update time in cells with timer

[tezza]

Hi

I'm trying to figure out a way to update a col of cells when a timer(ish) setup hits zero.

Here's what I have

A1 = 72 hours

B1 = set time

c1 = countdown to set time (b1) to 72 hours time (A1)

d1 = set time + A1

It's just a countdown timer from one time (b1) to another (d1) where (d1) is set 72 ahead using (a1)

The above bit is easy enough but I'm having trouble with once the 2 times meet hence the countdown = 00:00 I want the set time in B1 to d1, which then resets the timer in (b1) to (a1) hours, showing (d1) ahead by (a1) hours

Yes, it loops within itself with excel says 'no' but I'm not sure how to do it.

This will be repeated in all col's 126 times with each cell in col B with a different preset time but still being reset after the hours set by (A1).

How would I do this?

regards

 

[tezza]

nm