The IRS updates daily, during the overnight hours.
Taxpayers will begin to see refunds claiming EITC/ACTC the week of Feb. 27. “Where’s My Refund?” will update for EITC/ACTC refunds beginning Feb. 16, with the vast majority updating by Feb. 18.
https://www.irs.gov/uac/newsroom/avoid-the-rush-use-irsgov-for-quick-answers-to-questions
(You can always change your withholding so that you do not have to wait for a refund at tax time.)