try:

=SUMPRODUCT((MONTH(A1:A)=1)*(T1:T100))

assuming there only one year i.e one set oj January.

HTH

"judgejulz" wrote:

What formula can I use to get the sum of cells in 1 column, but only if that
cell corresponds to a date in January. For example, column A is the date
column and every cell has a different date in it and I want to get the sum of
all the entries in column T in January or February etc.