sumifs function

hi all
I need help on something I am trying to achieve, basically I am trying to use the sumifs function to add a column that is in pounds but with multiple criteria.
I am trying to add a price field but between two dates (between the beginning and end of each month) another criteria from a range of cells I have copied the formula I have written below

=SUMIFS(Sheet1!K:K,Sheet1!B:B,">="&I17,Sheet1!B:B,"<="&J17,Sheet1!W:W,"="&M17)

try to explain a little column K is the column I need to sum column B is the date field that I need to extract i.e. 1st to 31st January (I have put these dates in a cell that correspond to I17 and J17)
then the last bit column W is another criteria that I need met, this works for just one cell however if I try to add another criteria in another cell it doesn't work after M17 I add to the formula ,Sheet1!W:W,"="&M18)

can someone please help before I lose all my hair

thank a lot

Simon

SUMIFS is essentially an ANDing function, and the values can't equal whatever is in M17 AND M18, you need to OR those two.

So you could just double it up

=SUMIFS(Sheet1!K:K,Sheet1!B:B,">="&I17,Sheet1!B:B,"<="&J17,Sheet1!W:W,"="&M17)+SUMIFS(Sheet1!K:K,Sheet1!B:B,">="&I17,Sheet1!B:B,"<="&J17,Sheet1!W:W,"="&M18)

Happy days that works a treat thank you very much I get to keep some hair!!!