Can I extend my 30-day visa exemption today, or should I wait until closer to the expiration date?

A user inquires about the possibility of extending their 30-day visa exemption that expires on the 23rd. They ask if they can go today to extend it or should wait until closer to the expiration date. Comments suggest that in major cities like Bangkok, Chiang Mai, and Phuket, you can extend for 45 days or less if you are within the remaining period on your current stamp, but most other immigration offices may only grant 30 days or less for extensions.