Can I stay in Thailand for 90 days without a visa by extending my 60-day exemption?

The user seeks clarification on staying in Thailand for 90 days without a visa, assuming a 60-day visa exemption is extendable by 39 days. The comments reveal that the user can extend their 60-day visa exemption by 30 days (not 39) for a fee of 1900 Baht, but any extension must be applied for before the initial 60 days expire to avoid overstaying penalties. It is also noted that the first day of entry counts as day one, leading to a practical limit of about 89 nights in Thailand.