The six-hour clock: gongs, drums and strikes

Ask a Thai friend the time and you won't hear 'twenty hundred'. Spoken Thai splits the day into four six-hour blocks, each with its own word. ตี (strike) covers 1–5 am. โมงเช้า covers 6–11 am; โมง copies the sound of a gong. Noon is เที่ยง. Afternoon is บ่าย…โมง (1–3 pm), then โมงเย็น (4–6 pm). Night is ทุ่ม, the sound of a drum, counted again from one: หนึ่งทุ่ม is 7 pm, ห้าทุ่ม 11 pm. The trick: add 6 to the ทุ่ม number. Midnight is เที่ยงคืน. The system goes back to the gongs and drums that marked the hours in old Siam, and was standardised in 1901. Written schedules, hospitals and TV use the 24-hour นาฬิกา (20.00 น.), but massage shops, friends and Grab drivers use the spoken clock.