hi - I eventually used a combination of our formulas and others on this
website. This is the formula that worked:

=SUMPRODUCT(--(A10:A169=A33),--(B10:B1690))

I changed the "=1100" to =A33, which is of the cells that contains 1100.

Then there were (oddly) some data normalization issues (not all the cells
with 1100 and were formatted the same were the same to Excel, so I copied and
pasted to avoid the issue in the formula.)

Column B, above, is the column with date entries.

Many thanks to all who sent replies to help-out!

"Harlan Grove" wrote:

"Don Guillett" wrote...
try this, changing columns to suit
=SUMPRODUCT((F2:F12=1100)*(LEN(TRIM(G2:G12))0) )
....

Doesn't actually check for dates, just for either nonwhitespace text
or numbers in the second column range.

If the OP really means blank, then it'd be better to use either

=SUMPRODUCT((F2:F12=1100)*ISNUMBER(G2:G12))

or (more exacting by ensuring the number is a valid 1900-basis date
serial number)

=SUMPRODUCT((F2:F12=1100)*(G2:G12=--"1990-01-01")*
(G2:G12<=--"9999-12-31"))

But the OP's follow-up leads me to suspect the OP has a mixture of
text and numbers in the first column range, so more robust to use

=SUMPRODUCT((--F2:F12=1100)*(G2:G12=--"1990-01-01")*
(G2:G12<=--"9999-12-31"))