Ok, So I tried the following formula and still ended up with a value error:
=SUMPRODUCT((F5:F14=DATE(2009,7,1))*(F5:F14<=DATE (2009,10,31))*(DATE(18+YEAR(C5:C14),MONTH(C5:C14), DAY(C5:C14))X1,D5:D14)

Since the whole situation with leap year doesn't matter in this situation,
is there a basic formula I can insert into my original larger formula that
replaces the <18? I have several similar formulas to the original one and all
of them require that I change the term "18" to instead reflect birthdates
(some require less than 18, others require greater than or equal to 18). So,
adding in a separate column isn't really a possibility, and I have no idea
what Helper Cells are.

"JoeU2004" wrote:

"T. Valko" wrote:
EDATE won't work on arrays.

Busted! Thanks for pointing that out.

In light of that fact, I don't have a single-formula solution that
effectively does what EDATE would, namely ensuring that the 18th anniversary
of a 2/29 date is 2/28, if that is what the OP wants.

The only method I can think of requires helper cells.

My normal non-EDATE workaround is something like:

MIN(DATE(18+YEAR(C5),MONTH(C5),DAY(C5)),
DATE(18+YEAR(C5),1+MONTH(C5),0)

But that does not lend itself to a SUMPRODUCT or array formula, replacing C5
with a range like C5:C14.

An alternative is to create a column for the 18th anniversary date. Suppose
that's Y5:Y14. Put EDATE(C5,18*12) or the MIN formula above into Y5 and
copy down. Then the SUMPRODUCT formula becomes:

=SUMPRODUCT((F5:F14=DATE(2009, 7, 1))*
(F5:F14<=DATE(2009, 10, 31))*(Y5:Y14X1), D5:D14)

where, again, X1 might be =TODAY() or a recent evaluation date. And again,
X1 can be replaced with TODAY(), if that is what the OP truly wants.


----- original message -----

"T. Valko" wrote in message
...
If you cannot use EDATE()

EDATE won't work on arrays.

...(EDATE(C5:C14,18*12)...

That'll return a #VALUE! error.

--
Biff
Microsoft Excel MVP


"JoeU2004" wrote in message
...
"MSW Intern" wrote:
My current formula just uses <18, but that only works if I input
each person's age. I need to revise it so that it looks
at the birthdates in coorelation with the current date

If you are saying that C5:C14 will contain date of birth instead of age,
then:

=SUMPRODUCT((F5:F14=DATE(2009, 7, 1))*
(F5:F14<=DATE(2009, 10, 31))*(EDATE(C5:C14,18*12)X1), D5:D14)

where X1 might contain =TODAY(), or it might contain a specific date.
You can replace X1 with TODAY() if you wish.

(Usually we do not truly want "the current date", but instead some
current "evaluation date".)

I use EDATE() to be sure that a birthdate like 2/29/1992 is handled
correctly. I believe the person is considered 18 years on 2/28/2010, not
3/1/2010. If you get a #NAME error, see the EDATE help page.

If you cannot use EDATE(), then:

=SUMPRODUCT((F5:F14=DATE(2009, 7, 1))*
(F5:F14<=DATE(2009, 10, 31))*
(DATE(18+YEAR(C5:C14),MONTH(C5:C14),DAY(C5:C14))X 1), D5:D14)

But that does have the problem(?) that 3/1/2010 will be considered 18
years after 2/29/1992.


----- original message -----

"MSW Intern" wrote in message
...
Is there a way to have Excel consider a birth date to determine if the
person
is under 18 versus 18 and older? My current formula just uses <18, but
that
only works if I input each person's age. I need to revise it so that it
looks
at the birthdates in coorelation with the current date to determine
which
category the person falls into.
My current formula reads:
=SUMPRODUCT((F5:F14=DATE(2009, 7, 1))*(F5:F14<=DATE(2009, 10,
31))*(C5:C14<18), D5:D14)
I need to revise the part that says <18 to instead consider birthdates,
while keeping all the rest of this long formula. Please help!!