Private Sub cmb_Click()
Dim start, finish
start = DateSerial(Year(Date), Month(Date), 1)
finish = DateAdd("m", 1, start) - 1
DoCmd.ApplyFilter , "myDate>=#" & Format(start, "mm\/dd\/yyyy") & "# and myDate<=#" & Format(finish, "mm\/dd\/yyyy") & "#"
End Sub