Yes I know Tod is extremely knowledgeable and helpful ... actually all the moderators are on this site and there is no silliness which I appreciate too.
I am aware it needs to be in the month ..... I have set it up for early in the month to cover any processing delays.
I went into Chiang Mai Immigration a week before I was planning to renew. Had some questions and the very helpful guy at the desk added it was a waste of time making an appointment. I didn't ask why but ..... just get there at 7.30am, get a number and it shouldn't take too long.
Last week it was something of a circus at document checking so don't be much after 7.30! It only took 50 minutes once I was inside to be on my way!