I'm trying to calculate a start date based on a "need by" date.

For instance.....cell B30 in a worksheet has a "need by" date of 5/4/2006.
This date means I have to "start" the project 6 weeks before that.

I'd like the formula to back-calculate the "start" date based on the "need
by" date.

I've tried using EDATE but get a "#NAME" error. I've tried =DATE92006,5,4)
for the "need by" date but it still won't calculate backwards.

Any help would be appreciated.

Thanks a lot!