if month is less than halfway over subtract 1

[Guest]

I need an if formula that takes a date in cell K3 and determines if the month
in that cell is halfway over. If it is not halfway over, then it subtracts
the number 1 from cell A25. If the month is halfway over, then do nothing.
Is this possible, and if so, please let me know. Much obliged.

 

[N Harkawat]

=if(day(k3)<16,a25-1,"")

 

[Bernard Liengme]

Here is something to work with
=A25-(DAY(J3)<=INT(DAY(DATE(YEAR(J3),MONTH(J3)+1,0))+1)/2)
DAY find the day-of-month from the date
The Date part computes the last day of the month by finding the zeroth day
of the following month
Your may want to experiment with the 1 and the INT depending on your meaning
of "month is half over"
best wishes

 

[Bob Phillips]

=IF(DAY(K3)>DATE(YEAR(K3),MONTH(K3)+1,0)/2,A25-1,0)