it has been my experience to be at least an hour at the office I frequent and some headache medicine would be advised. And yes, remember, copies, copies, copies!
I also had to show a deposit slip, updated bank book, and also transaction history paperwork from the bank the day of application. Oh and give 2000baht. And don't forget...copies, copies, copies!
Its getting more and more difficult to open a bank account on a tourist visa. I first got a retirement visa non-o-a and qualified showing enough monthly income and also health insurance. I did secure a bank account and am now in the process of changing my visa from non-o-a to a non-o. One also has to show proof of 800,000baht in the bank 60 days prior to applying for a non-o visa which doesn't require health insurance. Confused yet?