Inserting countifs formula using vba.....having problem with date

I am trying to put the following formula into an excel sheet via vba.........

COUNTIFS(Inputfile_InQQR!$B$2:$B$7774, 9/1/2011)

but its giving me "0"

if i change the formula to this.........it works

COUNTIFS(Inputfile_InQQR!$B$2:$B$7774, "9/1/2011")

problem i am having is in my vba code i have a variable

current_month = "9/1/11"

But no matter what i try i can seem to get the date into the right format for this formula to be inserted correctly........any ideas?