Help with Dates in Formula

[cr2289]

Help please. I need a formula that will add 15% to a date. If the resulting date is a Saturday, the date needs to be moved back to Friday. If the resulting date is a Sunday, the date needs to move up to Monday.

Here's what I'm using now:
- B5 is a start date
- B6 is an end date
- B7 calculates the total number of days (=B6-B5+1)
- B10 needs to calculate the date in B5 + 15% (=B5+ROUND((B7*0.15),0)-1

Is the formula in B10 correct?
What is a formula that will automatically change B10 results from a Saturday to the previous day (Friday)?
What is a formula that will automatically change B10 results from a Sunday to the next day (Monday)?

Thank you so much for your reply.

 

[Peter_SSs]

- B10 needs to calculate the date in B5 + 15% (=B5+ROUND((B7*0.15),0)-1

Is the formula in B10 correct?

It looks reasonable but you will have to determine just what you want to happen in relation to rounding when the basic 15% calculation does not give an 'exact day'

What is a formula that will automatically change B10 results from a Saturday to the previous day (Friday)?
What is a formula that will automatically change B10 results from a Sunday to the next day (Monday)?

Assuming that your formula above was correct for adding the 15%, try this to add/subtract/leave alone as relevant.

=B5+ROUND((B7*0.15),0)-1+LOOKUP(WEEKDAY(B5+ROUND((B7*0.15),0)-1),{1,2,7},{1,0,-1})