Lanna Calendar 2027: Every Key Date of the Year

The Lanna calendar for 2027 sets out the whole Gregorian year 2027 (Thai year BE 2570) in Lanna days and months. In Kham Mueang a calendar is a pakkhatuen (ปักขฯทืนฯ, pakkhatuen), and our own system is the pakkhatuen lanna (ปักขฯทืนฯล้านฯนาฯ, pakkhatuen lanna). The dictionary describes it as a solar-lunar calendar: dates follow the sun, while the waxing and waning days follow the moon.

This post puts every northern month of 2027 in one table: when each month starts and ends, which days are holy days and bad days, and when the big merit festivals fall, from Si Peng in January and Lanna New Year in April to Yi Peng in November.

Tap through the months in the full-year calendar below.

Where 2027 starts and ends in the Lanna calendar

Lanna counts its months (duean, เดิอฯร) two months ahead of central Thailand. The first month of the cycle is Duean Kiang (เดิอฯรกยฯง, duean kiang), which matches the 11th month of central Thailand. The new era year (Chula Sakarat) begins in the seventh month, on Wan Phaya Wan in mid-April.

So this post follows the everyday year: 1 January to 31 December 2027. That span runs from the end of Duean Sam (สามฯ, sam, the third month) to the start of the next Duean Si (สี่, si, the fourth month).

The dictionary calls an odd-numbered month a duean kik (เดิอฯรคีกฯ, duean kik) and an even-numbered month a duean ku (เดิอฯรคู่, duean ku). The waxing half is the duean ok (เดิอฯรออฯก, duean ok) and the waning half the duean haem (เดิอฯรแรมฯ, duean haem). The 15th waxing night is peng (เพงฯ, peng), the full moon, and the 14th waning night, the last night of an odd month, is dap hon (ดัปฯห฿นฯ, dap hon).

The northern months of 2027 at a glance

In Kham Mueang a Buddhist holy day is a wan sin (วันฯสีลฯฯ, wan sin). The 8th waxing and waning days are wan sin noi (วันฯสีลฯฯห้นฯอฯยฯ, wan sin noi), "small holy days", and the full moon and the last day of the month are wan sin luang (วันฯสีลฯฯหลฯวฯง, wan sin luang), "great holy days". Full-moon dates are in bold.

Every date was calculated with the Moradok Lanna calendar. All dates are in 2027 unless a year is given. Temples may hold their merit events on different days, so check with your local temple.

Key dates of 2027 in order

Si Peng: the new-rice offering at the start of the year

The 15th waxing day of Duean Si falls on Friday 22 January 2027. By then the rice in the barns is new rice, and families make the tan khao mai offering (ทาฯนฯเขั้าไห่มฯ, tan khao mai). The dictionary explains it as offering the rice newly harvested that year, a rite held to be essential before anyone eats the new rice. Read about grilled sticky rice, bamboo rice and the fire for the Buddha in Tan Khao Mai.

Another Duean Si begins at the end of the year, and its full moon on Tuesday 11 January 2028 is the next year's Si Peng.

Lanna New Year 2027: Sangkhan Long, Wan Nao, Wan Phaya Wan

Pi Mai Mueang (ปีให่มฯเมิอฯง, pi mai mueang) is the Lanna New Year, the northern Songkran. It follows the sun, so it does not fall on the same dates every year. Our calendar gives these days for 2027:

• Sangkhan Long (สังขฯาน์ตฯล่อฯง, sangkhan long): Wednesday 14 April at 16:55.
• Wan Nao (วันฯเนาฯ, wan nao): Thursday 15 April. This year there is only one Wan Nao.
• Wan Phaya Wan (วันฯพยฯาวันฯ, wan phaya wan): Friday 16 April at 20:52. The dictionary explains it as the day the Chula Sakarat era year changes.
• Wan Pak Pi (วันฯปากฯปี, wan pak pi), the day after Wan Phaya Wan: Saturday 17 April.
• Wan Pak Duean (วันฯปากฯเดิอฯร, wan pak duean), the day after Wan Pak Pi: Sunday 18 April.

The great holy days and Buddhist Lent

The dictionary matches each major Buddhist day with its Lanna month. With no extra month this year, they all fall in their usual months.

• Wan Makha Puja (วันฯมาฆบูชา, wan makha puja) is the full moon of Duean Ha: Sunday 21 February.
• Wan Wisakha Puja (วันฯวิสาขบูชา, wan wisakha puja) is Paet Peng (แปดฯเพงฯ, paet peng), the full moon of the 8th northern month: Thursday 20 May.
• Wan Asanha Puja (วันฯอาสาฬหบูชา, wan asanha puja) is the full moon of Duean Sip: Sunday 18 July.
• Khao Wasa (เขั้าหลฯามฯวัªา, khao wasa), the start of Buddhist Lent: Monday 19 July.
• Ok Wasa (ออฯกวัสสฯา, ok wasa), the end of Lent: Friday 15 October.

After Lent comes the season for offering the pha kathin robe (ผ้ากฐิน, pha kathin). The dictionary says it may be offered from the 1st waning day of Duean Kiang to the full moon of Duean Yi, so in 2027 the season runs from Saturday 16 October to Saturday 13 November.

Tan Kuay Salak and Yi Peng: merit festivals at the end of the year

All of Duean Sip-song, 1–30 September 2027, is the season when temples hold kin kuai salak (กินฯกวฯยฯสๆลฯากฯ, kin kuai salak), the salakabhatta merit offering. The dictionary notes it is also called tan kuai salak or tan salak. Each temple picks its own day in this window. Read more in Tan Kuay Salak.

The year closes with Yi Peng (ยี่เพงฯ, yi peng), the 15th waxing day of Duean Yi, on Saturday 13 November 2027, about 11 days earlier than in 2026. For the whole month see Duean Yi, and for the festival's words see Yi Peng words.

Is there an extra month or an extra day this year?

A lunar calendar has to add a month or a day now and then so the months stay in step with the seasons. The dictionary describes two kinds:

• Athikamat (อธิกมาสฯฯ, athikamat) is a year of 13 months with two tenth months, called "tenth before" and "tenth after". In such a year the Buddhist holy days move one month later.
• Athikawan (อธิกวาฯรฯ, athikawan) is a year in which the ninth month has 30 days. When the ninth month has 29 days, it is a normal year.

2026 (BE 2569) was an extra-month year. 2027 has neither: Duean Kao (5 June to 3 July) has 29 days, so every holy day stays in its normal month.

The bad days of each month in 2027

Lanna people observe wan sia (วันฯเสยฯ, wan sia), or wan sia pracham duean (วันฯเสยฯระฯบจำเดิอฯร, wan sia pracham duean), the inauspicious days of each month. The dictionary records the verse the elders learned by heart: "Kiang, five and nine, bad on Sunday and Monday; Yi, six and ten, bad on Tuesday alone; three, seven and eleven, bad on Thursday and Saturday; four, eight and twelve, bad on Wednesday and Friday."

In the table above, the bad days of every month follow this verse. Duean Jet, the New Year month, for example, has Thursday and Saturday as its bad days. For the verse line by line, see Lanna bad days.

Summary

• The 2027 Lanna calendar runs from the end of Duean Sam to the start of the next Duean Si, with no extra month and no extra day.
• Lanna New Year: Sangkhan Long 14 April, Wan Nao 15 April and Wan Phaya Wan 16 April.
• Great holy days: Makha Bucha 21 Feb, Visakha Bucha 20 May, Asalha Bucha 18 Jul, start of Lent 19 Jul and end of Lent 15 Oct.
• Lanna merit festivals: Si Peng 22 Jan, Tan Kuay Salak all September, and Yi Peng 13 Nov.
• Each month's bad days follow the verse in the dictionary.

See the lunar date of any day in the Lanna calendar, look up more calendar words in the Moradok Lanna dictionary, and read the basics of counting months in Northern months and Duean Sam.

Sources

• Moradok Lanna dictionary: ปั๋กขะตืนล้านนา(https://moradoklanna.com/dict/?ปั๋กขะตืนล้านนา) · อะทิกะมาส(https://moradoklanna.com/dict/?อะทิกะมาส) · วันพญาวัน(https://moradoklanna.com/dict/?วันพญาวัน) · วันเสีย(https://moradoklanna.com/dict/?วันเสีย) · ผ้ากฐิน(https://moradoklanna.com/dict/?ผ้ากฐิน)
• Moradok Lanna calendar: daily calendar (every day of 2027 calculated on 18 October 2026) · Wan Phaya Wan, 16 April 2027
• Images from Unsplash and Wikimedia Commons, credited under each image