I would like to have the maximum stay on a tourist visa without doing a border run. I know that the first and last day count, so I really get 59 days on a tourist visa. Also, I can extend it by 30 days in Thailand to get 89 days. I am looking at booking a ticket that will arrive Nov. 14th at 11:55 pm ( 23:55 ). Can I assume that by the time I get to immigration, it will be Nov. 15th and I can stay until Feb. 12th?

Its a fair assumption that if your flt is scheduled to land at 11.55 then by the time you get off and walk to immigration it will be the next day, although whether or not the guy/gal on the desk bothers to change the stamp is another matter.

It is at the discretion of the officer. I wouldn't stress out about a day or two. If you really need some extra days and you have proof you are leaving Thailand you can get a second extension of 7 days for 1900 baht.

Thanks for your help. I have decided to get a two entry tourist visa. If they don't change the date on the stamp shortly after midnight, I will have the option of doing a border run or paying for 30 and 7 day extensions. If anyone on this message board has arrived just after midnight in Thailand, I would like to know if immigration updated the stamp before marking your passport.

With a two entry visa you can make one border crossing near the end of the 60 day stay and get a new 60 day entry to cover your full period of time and no 7 or 30 day extensions will be required.

If you're arriving at 2355 it will be well into the next day by the time your passport gets stamped unless you're flying solo. Why sweat about one day?

Thanks for your help. I have decided to get a two entry tourist visa. If they don't change the date on the stamp shortly after midnight, I will have the option of doing a border run or paying for 30 and 7 day extensions. If anyone on this message board has arrived just after midnight in Thailand, I would like to know if immigration updated the stamp before marking your passport.

Once again, you are at the whim of whatever Immigration desk you front up at. I recall a thread here where someone arriving after midnight got lucky as the particular Immigration desk officer hadn't changed his stamp. Chances are this was an aberration as I am sure that they are required to change the stamps as soon as possible after midnight. Definitely will be the correct date if the Immigration officer has just come on shift after midnight.

If the OP is so worried about one 'extra' day on arrival; maybe he should pay more attention to the date of planned entry and based on that entry, when the visa days expire. If expiration/extension falls on a Saturday or a holiday weekend and you are asleep at the wheel, you may end up 'losing' 3 or 4 days or risk an overstay, fine or both.