=IF(ISBLANK(a1),"",DATE(YEAR(a1),MONTH(a1), DAY(a1)+30))

"Eileen" wrote:

I am trying to enter a formula to calculate a date 30 days later in cell b1
only if cell a1 has a date. If cell a1 does not have a date then leave b1
blank. I am getting a return date of 30-Jan-00 when cell a1 is blank. I don't
understand why 30-Jan-00 comes up. This is the formula that I am using:

=IF(ISBLANK(A1),"",IF(COUNT(A1+30),A1+30,""))

Thank you in advance for your help.
Eileen