Approving an institution : time to do it

Hi,

I had registered my institution on my profile since the last lunchtime contest (in April) and it is not approved yet. So, my question is : how long does it take to do it ? In my case, it is not urgent at all (it is just a bonus, I think), but when I update my profile, I receive a mail to inform me that my institution is waiting for approval ;).

Thank you :).