When can I apply for the Covid extension in Thailand and when will it start?

The user is asking about the appropriate timing for applying for a Covid extension in Thailand, considering they entered under a visa exemption and have already received a 30-day extension. They are uncertain about when they can apply – whether they should do it before their current extension expires on 26/11, and when the 60-day Covid extension will start, noting the current extension runs out on 7/12.