Days of the Week in Thai (and Each Day's Lucky Color)

The days of the week in Thai are built from one word plus the name of a classical planet. Start with วัน (wan) — "day" — and add the celestial body: Monday is วันจันทร์ (wan jan), the "moon day," and Sunday is วันอาทิตย์ (wan aa-thít), the "sun day." Learn วัน once and the whole week falls into place, because every name follows the same วัน + planet pattern.

This is the same system Thai shares with Latin and Sanskrit — Monday for the moon, Saturday for Saturn — so once you see the logic you are really only memorising seven planet names. Days pair naturally with the rest of your first vocabulary; if you are just starting out, read them alongside your first words of Thai.

The pattern: วัน + a planet

วัน on its own means "day," and the seven day-names simply attach a planet borrowed from Sanskrit astrology. You do not conjugate anything and there are no gender particles inside the day-names themselves — a day is a day whoever is speaking. Here is the full set, with the tone marked on the part that trips people up:

• วันอาทิตย์ (wan aa-thít) — Sunday, from อาทิตย์, "the sun"
• วันจันทร์ (wan jan) — Monday, from จันทร์, "the moon"
• วันอังคาร (wan ang-khaan) — Tuesday, from อังคาร, "Mars"
• วันพุธ (wan phút) — Wednesday, from พุธ, "Mercury" — high tone on พุธ (phút)
• วันพฤหัสบดี (wan phrʉ́-hàt-sà-bɔɔ-dii) — Thursday, from พฤหัสบดี, "Jupiter"
• วันศุกร์ (wan sùk) — Friday, from ศุกร์, "Venus" — low tone on ศุกร์ (sùk)
• วันเสาร์ (wan sǎo) — Saturday, from เสาร์, "Saturn" — rising tone on เสาร์ (sǎo)

Thursday is the mouthful. The full, calendar-correct name is วันพฤหัสบดี, but in everyday speech almost everyone shortens it to วันพฤหัส (wan phrʉ́-hàt) — nobody blinks if you drop the บดี. That is the one abbreviation worth learning on purpose.

The lucky color for each day

Here is what phrasebooks skip: in Thailand every day carries an auspicious color, drawn from the color of the Hindu-derived deity who presides over it. It is not folklore you can safely ignore — it shapes what people wear.

• Sunday — red (สีแดง, sǐi dɛɛng)
• Monday — yellow (สีเหลือง, sǐi lʉ̌ang)
• Tuesday — pink (สีชมพู, sǐi chom-phuu)
• Wednesday — green (สีเขียว, sǐi khǐao)
• Thursday — orange (สีส้ม, sǐi sôm)
• Friday — light blue (สีฟ้า, sǐi fáa)
• Saturday — purple (สีม่วง, sǐi mûang)

Monday's yellow is the one you will actually see. The late King Bhumibol was born on a Monday, so yellow became his color, and to this day you will notice a wave of yellow polo shirts in government offices and on the BTS around royal anniversaries. Living in Bangkok, the giveaway that I had finally internalised the week was catching myself thinking "it's Monday, that's why the whole carriage is in yellow" before I had consciously worked out the date. If you want to go deeper on the color words themselves, they are all in the guide to Thai colors.

Today, tomorrow, and asking the date

Three time-words do most of the daily work:

• วันนี้ (wan-níi) — today ("this day")
• พรุ่งนี้ (phrûng-níi) — tomorrow
• เมื่อวาน (mʉ̂a-waan) — yesterday

For the calendar frame, "week" is สัปดาห์ (sàp-daa) in writing and formal speech, while "weekend" is cheerfully literal: เสาร์อาทิตย์ (sǎo aa-thít), just "Saturday-Sunday." To ask the date, say วันนี้วันอะไร (wan-níi wan à-rai) — "today is what day?". Here the politeness particle does depend on who is speaking: a man closes with ครับ (khráp) and a woman with คะ (khá), so วันนี้วันอะไรครับ or วันนี้วันอะไรคะ. That คะ is the high-tone question particle, not the falling-tone ค่ะ you would use to end a statement.

The mistakes to skip

The tone traps cluster on the short words. วันพุธ (Wednesday) takes a high tone — phút, not a flat "poot" — and I learned that the slow way, asking a market vendor which day her stall moved and getting a polite blank until I lifted the pitch. วันศุกร์ (Friday, sùk) is a low tone and วันเสาร์ (Saturday, sǎo) is rising; flatten either and you will be understood, but a Thai ear clocks it instantly. The Paiboon tone marks printed above every flashcard show you exactly where the pitch should sit.

The second slip is treating Thursday as unspeakable and avoiding it. Do not — just use the short วันพฤหัส (wan phrʉ́-hàt) and move on. And do not overthink "weekend": you do not need a fancy word, เสาร์อาทิตย์ is what people actually say.

Days of the week sit right beside numbers, colors, and greetings in the everyday core — study them together with the rest of the essential Thai phrases, run the deck above in both directions, and วัน plus its seven planets will come out without a pause.