Can Immigration Officials grant less than a 30-day stamp if I mention my short stay in Thailand?

When entering Thailand, the Immigration Officer (IO) generally follows fixed entry schemes based on the traveler's passport country, which stipulate a specific range of days (14, 30, or 90 days). Even if a traveler claims they are staying for a short duration, the IO cannot arbitrarily shorten the stay below the country's allotted entry scheme. Long-term stays and visa histories may lead to more detailed questioning, but ultimately, the allowed duration is standard and not subject to personal discretion.