Yalda Night 2026 falls on the evening of Monday, 21 December, and runs until dawn on Tuesday, 22 December. In Iran it is the night between 30 Azar and 1 Dey 1405, the longest night of the year: about 14 hours 16 minutes of darkness in Tehran. Families stay up late with pomegranates, watermelon, nuts and the poetry of Hafez.
Key takeaways
- Yalda Night, also called Shab-e Chelleh, falls on the evening of Monday, 21 December 2026, the night between the last day of Azar and the first day of Dey in the Iranian solar calendar.
- It marks the longest night of the year in the Northern Hemisphere: in Tehran the sun is down for about 14 hours 16 minutes, from the evening of 21 December until the morning of 22 December (US Naval Observatory).
- The December solstice itself comes at 20:50 Universal Time on 21 December 2026, which is after midnight in Iran, in the middle of the Yalda vigil (US Naval Observatory).
- UNESCO inscribed Yaldā/Chella on its Representative List of the Intangible Cultural Heritage of Humanity in 2022, as a joint element of Afghanistan and Iran, describing red fruits, nuts, sweets, poetry, stories and music.
When is Yalda Night in 2026?
Yalda Night 2026 is the evening of Monday, 21 December, lasting until sunrise on Tuesday, 22 December. Three independent guides updated for the 2026 season, from Remitly, the Iranian tour operator Surfiran and Iran’s Travel, give that night, and Remitly and Surfiran both give the Iranian date as the night of 30 Azar 1405. UNESCO describes the festival as held on the last night of autumn, and the US Naval Observatory puts the end of autumn, the December solstice, on 21 December 2026.
The rule behind the date is in the Iranian solar calendar, the Solar Hijri calendar that Iran uses for civil life. Yalda is the night between the last day of the ninth month, Azar, and the first day of the tenth month, Dey. The year begins at Nowruz, near the March equinox; the first six months have 31 days and the next five 30. In 1405, 1 Farvardin falls on 21 March 2026, so 1 Dey falls on 22 December 2026 and 30 Azar on 21 December.
| Calendar | Yalda Night 2026 |
|---|---|
| Iranian (Solar Hijri) | Night of 30 Azar into 1 Dey 1405 |
| Gregorian | Evening of Monday, 21 December, to dawn on Tuesday, 22 December |
| December solstice | 21 December, 20:50 Universal Time (US Naval Observatory) |
Why is Yalda the longest night of the year?
Because it sits on the December solstice, when the Northern Hemisphere is tilted farthest from the sun. In Tehran on 21 December 2026, the sun is up for about 9 hours 45 minutes and down for about 14 hours 16 minutes (US Naval Observatory).
The solstice instant in 2026 falls at 20:50 Universal Time, after midnight on Iran Standard Time (UTC+3:30). So in Iran the astronomical turning point comes in the small hours of Yalda itself, while families are still around the table. After that night the days lengthen again: the light comes back, the idea at the heart of the festival. For why the earliest sunsets arrive a couple of weeks before the solstice, see why the earliest sunset comes before the winter solstice; for how astronomers and meteorologists date the season, see when does winter start.
What does Yalda mean, and what is Chelleh?
Yalda means “birth”. The word was borrowed into Persian from Syriac, where yalda means birth and was also a Syriac name for Christmas; when and how it entered Persian is unclear (Wikipedia, citing the Dehkhoda dictionary). Anadolu Agency’s report also translates it as night of birth.
Chelleh, meaning “fortieth” (from the Persian word for forty), names the other side of the night. Shab-e Chelleh opens a 40-day stretch of deep winter, so the night is both a birth of light and the doorway to the coldest weeks.
Where does Yalda come from?
Yalda is pre-Islamic and Iranian, from the centuries when most Iranians followed Zoroastrianism, and its exact origins are debated. Anadolu Agency dates it to that pre-Islamic period. In the Zoroastrian picture of the world, the forces of Ahriman, the spirit of darkness, were thought to be at their strongest on the longest night, and the earliest customs were meant to protect people from that harm (Wikipedia). Staying up together grew out of that idea.
Two popular claims need care:
– Mithra’s birthday. Many popular accounts say Yalda celebrates the birth of Mithra, the ancient Iranian divinity of covenant who is linked with light and the sun. A related theory by the journalist Hashem Razi (1979), that Mehregan, Mithra’s festival, shifted to the winter solstice in early Islamic times, has a wide following online, but while scholars accept his documentation, they have not accepted his conclusion (Wikipedia). We grade the Mithra link as cultural: a meaning many give the night, not established history.
– Exact antiquity. Claims that Yalda is thousands of years old, or that an Achaemenid king added it to an official calendar, circulate widely on thin evidence. What is documented is a pre-Islamic solstice night that survived into Islamic-era Iran.
How do people celebrate Yalda Night now?
With family, food and poetry, late into the night. UNESCO describes families gathering at the homes of elders around a table with symbolic items: a lamp for light, water for cleanliness, and red fruits for warmth.
- Red fruit. Pomegranates and watermelon lead, alongside grapes, jujube and beetroot (UNESCO). Anadolu Agency reports that pomegranates take the most important place on the table. The red is often read as the glow of dawn and of life.
- Nuts, dried fruit and sweets. Bowls of nuts and dried fruit, sweets and a special broth fill out the table (UNESCO).
- Fal-e Hafez. Someone, often the eldest, reads from the Divan of the 14th-century poet Hafez, and many families practise fal-e Hafez: a question or wish in mind, the book is opened at random and the verse read as a guide to the year ahead (Anadolu Agency).
- Stories, music, games and gifts. UNESCO lists reciting poetry, storytelling, games, music, and gifts for new in-laws, brides and children.
- Staying up. Gatherings run past midnight and, for some families, toward dawn (Anadolu Agency).
Families traditionally sat around the korsi, a low heated table covered with a quilt. Wikipedia lists observance in Iran, Afghanistan, Tajikistan, Uzbekistan, Azerbaijan, Turkmenistan and among Kurds; UNESCO’s 2022 inscription names Afghanistan, where the night is called Chella, and Iran.
What does tradition say, and what does the evidence say?
Many cultures mark the darkest stretch of the year with light and company, from Sweden’s St. Lucia Day to Lidong, the Chinese start of winter. Yalda’s shape is its own: one long night, kept awake together, with poetry at its center.
| Tradition says | Evidence says | Grade |
|---|---|---|
| Yalda is the longest night of the year | Yes: it falls on the December solstice (US Naval Observatory) | fact |
| Staying awake guards against the dark | A protective custom from Zoroastrian belief | cultural |
| Red fruits bring warmth and health through winter | A symbolic meaning; no health claim is tested here | cultural |
| Yalda is Mithra’s birthday | A popular belief; not established by historians | cultural |
Your day on My BodyClock
The day above on My BodyClock is Monday, 21 December 2026, planned for a Yalda Night at the grandparents’ home. It is a working Monday, so the plan front-loads daylight with a walk soon after waking. Late afternoon goes to a market run for pomegranates, watermelon and nuts, then the drive over to set the table. Dinner comes at 7 PM, the fruit and Hafez follow, and stories and music carry the family past midnight. Home and lights low by 12:30 AM, asleep by 1 AM.
One late night does not have to cost the week. Light timing moves the body clock: evening light delays it and morning light advances it (Blume and colleagues, 2019). So the plan keeps lamps warm and low through the late evening, then wakes at 8 AM, only an hour after the usual time, and gets outside early. That is the same anchor-and-light idea behind how to fix your sleep schedule, and steady wake times across the week are worth protecting: in observational research, irregular sleep is linked with higher risk of death (see irregular sleep and death risk).
Plan your own Yalda in Owaves: take the Body Clock Type quiz, download Owaves on the App Store, or join the Android waitlist.
FAQ
What date is Yalda Night in 2026?
Yalda Night 2026 is the evening of Monday, 21 December, running until dawn on Tuesday, 22 December. In the Iranian calendar it is the night between 30 Azar and 1 Dey 1405.
Is Yalda on 20 or 21 December?
It depends on the year, because Yalda follows the Iranian solar calendar, whose months are tied to the sun. In most years it falls on the night of 20 or 21 December; in 2026 it is 21 December.
What do you eat on Yalda Night?
Red fruits lead the table, above all pomegranates and watermelon, with grapes and jujube. Nuts, dried fruit, sweets and a special broth are served too, according to UNESCO’s description of the festival.
Sources
- UNESCO Intangible Cultural Heritage. Yaldā/Chella (inscribed 2022, 17.COM; Afghanistan and Iran). https://ich.unesco.org/en/RL/yalda-chella-01877
- Rush, C. Yalda Night 2026: Dates, Meaning, and Traditions. Remitly (5 November 2026). https://www.remitly.com/blog/lifestyle-culture/yalda-night-dates-meaning-and-traditions/
- Iran’s Travel. Yalda Night in Iran: The Longest Night of Light and Love. https://iranstravel.com/yalda-night-in-iran/
- US Naval Observatory. Earth’s Seasons and Apsides, 2026. https://aa.usno.navy.mil/api/seasons?year=2026
- US Naval Observatory. Sun and moon data, Tehran, 21 December 2026. https://aa.usno.navy.mil/api/rstt/oneday?date=2026-12-21&coords=35.69,51.39&tz=3.5&dst=false
- US Naval Observatory. Sun and moon data, Tehran, 22 December 2026. https://aa.usno.navy.mil/api/rstt/oneday?date=2026-12-22&coords=35.69,51.39&tz=3.5&dst=false
- Anadolu Agency via Daily Sabah. Iran’s Yalda greets triumph of light over dark with poetry, fruits (20 December 2021). https://www.dailysabah.com/arts/irans-yalda-greets-triumph-of-light-over-dark-with-poetry-fruits/news
- Wikipedia. Yalda Night. https://en.wikipedia.org/wiki/Yalda_Night
- Blume C, Garbazza C, Spitschan M. Effects of light on human circadian rhythms, sleep and mood. Somnologie 23(3):147-156 (2019). doi:10.1007/s11818-019-00215-x. https://pmc.ncbi.nlm.nih.gov/articles/PMC6751071/
- SURFIRAN Magazine. Yalda Night 2026: Warmth On The Longest Night (updated 2 November 2026). https://surfiran.com/mag/yalda-night/
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