How long will it be before an instant transfer goes into my account?

I used the Instant Transfers from Apple Pay to my bank account. I accepted money from a friend through messages set up my Wallet and have been trying to transfer that money. I have done an I stand transfer the app says “Approved” but the money has not went into my bank account. How long will it be before the money finally goes into my account?

[Re-Titled by Moderator]