Hi experts,

I'm using this formula to highlight the first occurrence of each name in column A:

=IF(COUNTIF($A$4:$A$1000,A4)=1,0,COUNTIF($A$4:A4,A4)=1)

however, i need to modify this formula to highlight the first occurrence of each name each month of every year.

The dates are listed in column B.

Please help.