If all you have is the month name as a TEXT entry:

A1 = April or Apr

=DAY(DATE(YEAR(A1&1),MONTH(A1&1)+1,0))

Returns the number of days for the month *of the current year*. Where that
might be important is in a leap year.

Biff

"T. Valko" wrote in message
...
If you have a date:

A1 = some date like 4/12/2007 (April 12 2007)

=DAY(DATE(YEAR(A1),MONTH(A1)+1,0))

Returns 30

Biff

"dipsy" wrote in message
...
I know the month and want a formula that will tell me number of days in
the
month. For example, April would be 30 days and May would be 31 days.