Count Number by Month
Array formula where we count the number of cells where a date is in a particular month.
Remember To tell Excel that your formula is an array, hold the Ctrl & Shift keys while pressing Enter. Brackets {} will be displayed around it.
{=SUM(IF(LEFT(TEXT(B3:B14,"mmddyy"),2)="12",1,0))}
Starting from the middle, take the dates in B3 through B14 and convert to text in the format mmddyy. Grab the left 2 characters (mm) and look for 12. If found add 1, if not add zero.
