I've noticed on my Area51 profile page that my visited days are greater that my member days, how is this possible?
It is because you were registered for 46 whole days however, you have visited on that part day as well. Therefore you have visited 47 days, however the member for is only incremented at 6 PM Central Time. The member for 46 days is rounded down. Say you have 46.9 days (5PM Central Time), it is still rounded down to 46.