I might be wrong, and if I am one of the members who have been here longer than me, or a staffer can correct me.
I think the number or amount of time is only known by staff, and I think it's set that way to prevent people from spamming the board to reach a set number just to get access to certain features of the forums.
Simply interact by posting on threads that pique your interest, and when you reach the required number or amount of time, the other options will become available.