Pretty pedantic question - my mom entered on a 60 day tourist visa and needs to renew for another 30 days. How and when should she best go about this in Bangkok? The visa is valid until Jan 3rd, but she entered on November 9th with the Used stamp.
TLDR : Answer Summary
Your mom can apply for a 30-day Extension of Stay at the Bangkok Immigration Office before her current 60-day tourist visa expires on January 3rd. It's recommended to visit on a weekday, ideally between 9:15 and 9:30 AM to avoid crowds, especially on Mondays and Fridays. Alternatively, she can use the services at Bumrungrad Hospital for the extension, which requires an initial paperwork drop-off on a weekday and a return visit on Saturday. The total fees vary based on whether you go directly on Saturday or prepare in advance. Make sure to check for any holidays when the immigration office may be closed.