We process withdrawals at 8pm ET Monday - Friday, with a cut off at 7pm ET. 
You can pay $9 for a same day withdrawal. The money will hit your account shortly after 8pm ET if you submit before 7pm ET. (excluding weekends)
Regular withdrawals take 5 business days to process. If you withdraw on Monday before 7pm, you will get your money next Monday.

You can always check the notification in the middle of your screen to see when your withdrawal will be processed.