Are you taking about setting up a bank account? If so you can’t do so online. You have to do in person. Almost impossible task these days without a long term visa (and many reports of issues even with one).
It’s not a time of day thing. It’s up to 3 days prior. If you’re say arriving on a Sunday then the stroke after midnight on the Thursday (so Friday morning) you can apply regardless of what actual time you will arrive on Sunday.
You need 800k in the bank for 2 months prior to application. The fact you already had an extension means you need to have followed the rules for that one which would have been to keep the 800k for 3 months after your extension and not go below 400k for the remainder of the year - and then back up to 800k two months prior to application.
Ok. Couple of things here to keep in mind. The OP isn’t trying to transfer funds INTO their Thai bank. They are trying to transfer more than 50k from their bank to someone else’s.
This is a newish rule that doesn’t affect only K Bank but most. It has something to do with the facial recognition system the banks are using to allow transfers over 50k. This system doesn’t yet support use by foreigners.
Different banks have implemented different policies to get around this. My bank SCB used to have you go into the branch to sign a waiver that you’d allow transfers over that amount. Last month they said that would no longer work and you’d have to called their call centre to override the limit for a set period of time.
I’m sure other banks have similar systems in place rather than you actually having to go into a branch to transfer - but I can’t confirm this as I don’t have account with others.
SCB have said they are working on a “workaround” but haven’t got there yet.
If Bangkok Bank haven’t implemented this yet I’m sure they will soon. Perhaps not but we will have to wait and see.