It will usually take the IRS about 48 hours maximum to accept or deny your return.
After your return is accepted it will be sent to the IRS for processing. The IRS estimates about 21 days to process returns it can be longer or shorter depending upon the return and also the volume of returns they are dealing with.
You can check the status of your refund through the IRS the following link:
https://www.irs.gov/Refunds