How soon can I extend my Single Entry Tourist Visa by 30 days

[Ohphuket]

I'm here on a 60 day SETV which expires in about 2 weeks. I would like to get a 30 day extension from my local immigration office.

 

Can I go to the Immigration office early to get my 30 day extension, perhaps 1 week before it expires?

 

Also, I'm assuming that the 30 days is added to the expiry date. So if the expiry date was 01/01/2022, and I visited the immigration office on 24/12/2021, my new stamp would be until 31/01/2022?

[tonray]

Yes you can go now and get 30 days added to date