At least once a month there is some asking a question like this in this immigration and visa topic forum area,

"Will the Thai consulate and/or immigration be open in (pick a place) on (pick a holiday)"?

I know this won't do any good, but do you know that every year the Thaivisa forum posts a calendar of all Thai public holidays in Thailand?

The Thai Public Holidays calendar for 2013 has now been posted on this Thaivisa forum

It is in the General topic here and is pinned there.

Someone went out of his or her way to take the time to post it there,

As I said this probably won't do any good, but before someone asks another. "Will immigration be open on" ? question please take a look at that calendar.

It may have the answer to your question.

And YES New Year's Day 1 January 2013 IS a public holiday in Thailand.

Most Thai consulates in any country will be closed on Thai public holidays.

Perhaps more important December 31st is a public holiday every year in Thailand (which is not so common).

http://www.thaivisa.com/forum/files/file/674-thaivisa-calendar-2013/

just adding the direct link (as i myself was looking WHERE the GENERAL topic was hiding ) THX for posting the calender

A list of holidays is here:

Public Holidays 2013