The IRS says to give it up to 5 days, before it is actually posted
"It takes additional time for refunds to be processed after leaving the
IRS, and for financial institutions to accept and deposit them to bank
accounts and products like debit cards. Also many financial institutions
do not process payments on weekends or holidays, which can affect when
refunds reach taxpayers. For EITC and ACTC filers, the three-day holiday
weekend involving President’s Day affects their refund timing."
https://www.irs.gov/individuals/refund-timing