What are the bank balance requirements for the Non-O retirement visa in Thailand regarding the 800k baht rule?

The requirement for the 800,000 THB bank balance for the Non-O retirement visa is that it must be maintained in the bank for 3 calendar months after the extension is granted. This period is typically calculated from the date the extension application is submitted and approved, indicating that the funds need to have been present for 2 months prior to application and remain for 3 months post-extension.