After you file

The IRS takes some test returns before their official open date, which is Jan 23.  But they don't start processing refunds until the start date.

Also, if your return was taken in a test batch early, and rejected and you send it back, it is not clear whether it will be looked at again early because it was in the test batch, or if the resubmitted return won't be looked at until after the 23rd.