Weights and Measures
The metric system was officially introduced by a law passed on December 17, 1923. However, old Thai units are still in common use, especially for measurements of land. The traditional units convert into metric units as follows: 1 picul = 60 kg; 1 catty = 600 grams (100 catty = 1 picul); 1 baht (named like the currency, used to weigh gold) = 15.16 grams; 1 carat = 20 centigrams (5 carat = 1 gram); 1 sen = 40 meters; 1 wah = 2 meters (20 wah = 1 sen); 1 sauk (¼ wah) = 0.50 meter; 1 keup (½ sauk) = 0.25 meter; 1 rai (1 sq sen) = 1,600 sq meters; 1 ngan (¼ rai) = 400 sq meters; 1 sq wah = 4 sq meters (100 sq wah = 1 ngan); 1 kwien = 2,000 liters; 1 ban = 1,000 liters (2 ban = 1 kwien); 1 sat = 20 liters (50 sat = 1 ban); 1 tannan = 1 liter (20 tannan = 1 sat).
In 1940, Thailand moved its New Year’s Day from April 13 to January 1 to bring the country in line with most of the world. Until today, the old New Year’s Day (Songkran) is a holiday, and festivities are at least as exalted as on December 31 and January 1.
While a solar calendar has been used for a long time to count years, a lunar calendar is in use until today to set the dates of religious holidays (as it is the case with Easter in the Christian religion). And while Thailand switches to a new year at the same day as Christian countries, the years are still counted as Buddhist Era (B.E.) and not as Anno Domini (A.D.). 2484 B.E. was set as 1941 A.D.
The Buddhist Era started 543 years earlier than the Christian Era. Therefore 1957 A.D. was the year 2500 B.E. and 2000
A.D. was 2543 B.E. While postal stamping indicates Buddhist Era, bank matters are usually conducted in accordance to the Christian count.
The time zone of Thailand is GMT + 7 hours.