ATTENTION ALL MEMBERS
All immigration offices in the country will be closed tomorrow the 31st of Dec and Monday the 3rd of January.
Plan accordingly
NOTE: IF you have a stamp that is expiring on a date the immigration office is closed (weekends or holidays) and you go the first day they're open after the closure you can apply for your extension like normal and you will not be fined for overstay. You will get an overstay stamp in your passport thought but it will say fine waived due to holiday.
TLDR : Answer Summary
All immigration offices in Thailand will be closed on December 31st and January 3rd. If your visa stamp is expiring during this period, you can apply for an extension on the first business day after the closure without incurring a fine for overstay, although it will be marked in your passport.