What are the immigration office closures in Thailand for April 2021 and how does it affect visa extensions?

This is the way it works people.

IF you have a stamp (entry or extension) that expires on the date the immigration office is closed (weekends or holidays) and you go to the immigration office the very next day they're open (which in this case is next Friday the 16th) you will not be charged for overstay and can get your extension like normal.

You WILL get an overstay stamp in your passport but it will say overstay fine waived due to closure.