You should review the OSC to 226.36 Here is a link http://www.bankersonline.com/regs/226/suppi226-36.html
I take two things from it:
1)it's not the date of crediting that matters, it's whether a delay in crediting causes extra fees, interest, negative credit reporting, etc.
2)the 5:00 example in 226.36(c)(2)only addresses payments recieved by mail and is only an example. The comment right before it states that a bank may specify reasonable cut-off
times in writing--I sent a notice to our existing customers and include the same notice with disclosures for new loans.
226.10 is much stricter than 226.36