In Thailand, Laos, and Cambodia, the traditional system of noting hours is the six-hour clock. This reckons each of a day's 24 hours apart from noon as part of a fourth of the day. 7 am was the first hour of the first half of daytime; 1 pm the first hour of the latter half of daytime; 7 pm the first hour of the first half of nighttime; and 1 am the first hour of the latter half of nighttime. This system existed in the Ayutthaya Kingdom, deriving its current phrasing from the practice of publicly announcing the daytime hours with a gong and the nighttime hours with a drum. It was abolished in Laos and Cambodia during their French occupation and is uncommon there now. The Thai system remains in informal use in the form codified in 1901 by King Chulalongkorn.