If you go to all rankings, you will see a list that says Current Leaders. What is the time for current leaders? Is it like most points in the last hour? Or what?
The current leaders is actually the running tally for the current month we are in. As you can see from the leaders below it, it shows Last Month's leaders (I'm pretty sure!)
Anyways... I don't think it is instantly updated... so don't count on it showing exactly how many AP you have earned this month if you are one of the current leaders.