Hi all,

Through some assistance from excel forum members I was able to put together this sheet - see attached. Forum Query D1.xlsx

It's function is to calculate the end time of a task, taking into account various non-working time. All the formula's are shown, and anybody could use this to aid in their own planning.

I am now interested in trying to reverse this, such that I can enter in an expected completion time, and produce the lastest possible start time.

I don't think that the functions are that complex to understand but my problem is that I'm not mathematically inclined and would end up frustrated as hell trying to work it out. I wonder if somebody could take a look and offer their ideas.

Cheers