Five days, not one. At least three different stories explaining it, depending on where you ask. Observance in four religions with four different reasons. And a pollution problem serious enough that an honest article has to address it.
For a student in India during Diwali, it is the most visible thing that will happen to them, and it is worth knowing what is going on.
When It Falls
The rule: the new moon of Kārtika, by amānta reckoning, which places it in October or November. The five days run from two days before that new moon to two days after.
In 2026, the main day, Lakṣmī Pūjā, falls on 8 November.
As the calendar article explains, the main night is the darkest of the lunar month, which is the point of a festival of lamps.
The Five Days
Each has its own name and its own observance.
Day one, Dhanteras. Houses are cleaned and decorated with lamps and rangolī. Purchases are made, particularly gold and household goods, as a mark of renewal and an auspicious beginning.
Day two, Naraka Caturdaśī, also called Choṭī Diwālī. Sweets are bought, visits made. Some observe bathing rituals before sunrise; some light a lamp facing south for Yama, the deity of death.
Day three, Lakṣmī Pūjā. The main day, on the darkest night. Worship at home, new clothes, lamps, fireworks, feasting. This is the night temples and homes across several religions are lit.
Day four, Govardhan Pūjā or Annakūṭ. Commemorating Krishna lifting a mountain to shelter a community, and in some regions marking the bond between spouses.
Day five, Bhāī Dūj. Sisters perform rites for their brothers' wellbeing and receive gifts.
Two observations. The festival moves from cleaning and acquiring, through the main worship, to two days about relationships. And the deity of death gets a lamp on day two, which sits oddly in a festival about prosperity and is the kind of inclusion this tradition does not avoid.
The Competing Stories
There is no single explanation, and the regional differences are substantial.
Rāma's return. Rāma, Sītā, Lakṣmaṇa and Hanumān reach Ayodhyā after fourteen years of exile, following Rāvaṇa's defeat, and the city is lit to welcome them. This is the dominant northern account.
Krishna and Narakāsura. Krishna kills the demon Narakāsura and frees sixteen thousand imprisoned women. Prominent in the south, and the source of day two's name.
Lakṣmī's emergence. The goddess arises from the churning of the ocean, which connects the festival to her iconography and to the main day's worship.
What to take from the multiplicity. A festival with three origin stories is a festival that absorbed several observances. The lamps and the new moon are the constant; the narrative attached to them varies by region, and a student told one story has been told one of three.
Four Religions, Four Reasons
This is the part that surprises people and it is worth stating accurately.
Hindu. The accounts above, with Lakṣmī's worship as the main day's content.
Jain. Diwali marks Mahāvīra Nirvāṇa Divas, the final liberation of Mahāvīra, the twenty-fourth Tīrthaṅkara. The lamp tradition is traced to a proclamation by eighteen kings that lamps be lit in remembrance of the great light.
Sikh. Bandī Chhoṛ Divas, commemorating the release of Guru Hargobind from imprisonment at Gwalior Fort by the emperor Jahangir.
Buddhist. Observed among Newar Buddhists in Nepal, who offer prayers to Lakṣmī within their Vajrayāna practice.
Four traditions, one date, four unrelated reasons, all involving light. A student should know that a Diwali greeting in India may be to someone observing something quite different from what they assumed.
The Pollution Problem
This has to be addressed rather than skirted, and the figures are specific.
Air quality during Diwali is severely affected. During the 2023 festival, New Delhi briefly recorded the worst air quality in the world, with an index reading of 680 on one night.
Firecracker emissions contain heavy metals. Copper, zinc, sodium, lead, magnesium and cadmium, along with oxides of sulfur and nitrogen. Exposure causes eye, nose and throat problems, and the effects on people with respiratory conditions are considerably worse.
And there is a burn-injury pattern. One type of firework, the anār or fountain, has been found responsible for the majority of burn injuries during the festival.
What this means practically for a visitor.
If you have asthma or any respiratory condition, the main night and the following morning are genuinely hazardous in cities. Stay indoors with windows closed, and consider that this is a reason to be somewhere other than Delhi.
Rishikesh is better than the metros and not clean. Expect smoke.
And the debate is live in India. Firework restrictions, green crackers and court-ordered limits are contested annually, with real arguments on both sides about tradition, livelihoods and air. A visitor should know it is an internal argument and not a settled matter.
Lamps are the traditional observance. Fireworks are a later addition and the part causing the harm, which is worth knowing when the festival is described as a festival of lights.
The Lamp Itself
Worth a section, because the object is the festival and it is simple enough to describe exactly.
A dīpa or dīyā is a small open clay dish with a lip, filled with oil, with a cotton wick laid in it so the tip rests on the lip. Mustard or sesame oil traditionally, and ghee in temple use.
Three features worth noticing.
It is the cheapest possible light. Unfired or lightly fired clay, a little oil, a twist of cotton. A festival whose central object costs almost nothing is one that nobody is excluded from.
It is also disposable. The dishes are made in enormous numbers each year by potters and are frequently not kept. As with the Gaṇeśa images at their own festival, the object is made to be used for a few days.
And the word is in Diwali's name. Dīpāvalī, from dīpa, lamp, and āvalī, a row or series. A row of lamps, which is literally what is placed along a wall or a step.
The practical note for a visitor: clay lamps are sold everywhere in the week before, cost very little, and are easy to light with oil from any shop. A row of them on a windowsill is the observance, and nobody will object to a foreigner doing it.
For Teachers
Say it is five days. Students assume one. The structure, from cleaning through to sibling rites, tells them more than any explanation of meaning.
Give all three stories. Rāma, Krishna and Narakāsura, Lakṣmī's emergence. A festival with three explanations absorbed several observances, which is how festivals work.
Mention the four religions. It prevents a student assuming a greeting means one thing, and it is genuinely interesting.
Address the air quality. Especially to students with respiratory conditions, who need to plan for it. Treating the pollution as impolite to mention does them no favours.
And separate the lamps from the fireworks. The first is the tradition, the second is the addition, and the distinction is useful well beyond this festival.
For a Student in India
Practical, in order of usefulness.
It is a public holiday and things close. Shops, offices and transport are reduced for several days. Plan travel around it.
Courses usually continue with schedule adjustment, and many schools mark the main night.
Sweets will be offered to you, repeatedly. Refusing is awkward and accepting is easy; taking one and eating a portion of it is the normal compromise.
Noise is continuous for several nights. If you sleep lightly, earplugs are not an overreaction.
And the lamps are worth seeing. The ghats here, and any street with houses on it, are lit with oil lamps. That is the festival at its best and it costs nothing to walk out and look at it.
One courtesy. Dhanteras purchases and Lakṣmī Pūjā at home are family observances. An invitation to one is a real invitation, and arriving with sweets is the convention.
What a Practitioner Can Use
The cleaning. The festival begins with physically cleaning the house, and the account of Lakṣmī's arrival is that she enters a house that is clean and lit. Prosperity following preparation is a sober theology, and the practice is available to anyone with a room.
The darkest night. Lamps on the new moon of the month. The observance is placed at the point of least light, deliberately.
The lamp as the tradition and the fireworks as the addition. Useful for distinguishing what a festival is from what has accumulated around it.
And the day for Yama. A lamp facing south for the deity of death, inside a festival of prosperity. A tradition that does not partition the uncomfortable is consistent in this, and the Śrī Rudram's salutations are the same instinct.
Frequently Asked Questions
When is Diwali?
The new moon of Kārtika by amānta reckoning, in October or November, with the five days running from two days before to two days after. In 2026 the main day falls on 8 November.
Why is it on the darkest night?
Because it is a festival of lamps, placed at the point of least light in the lunar month. The timing is deliberate.
What are the five days?
Dhanteras, cleaning and purchasing; Naraka Caturdaśī, sweets and visits; Lakṣmī Pūjā, the main worship; Govardhan Pūjā, Krishna lifting the mountain; and Bhāī Dūj, rites between siblings.
What story explains it?
Three do, by region. Rāma's return to Ayodhyā after fourteen years of exile, Krishna's killing of Narakāsura, and Lakṣmī's emergence from the churning of the ocean.
Which story is correct?
All three are traditional. A festival with three origin accounts absorbed several observances, and the constants are the lamps and the new moon.
Do other religions observe it?
Yes, for different reasons. Jains mark Mahāvīra's final liberation, Sikhs mark Guru Hargobind's release from Gwalior Fort, and Newar Buddhists in Nepal offer prayers to Lakṣmī.
Is the pollution really a problem?
Yes. New Delhi briefly recorded the world's worst air quality during the 2023 festival, at an index of 680 on one night, and firecracker emissions contain heavy metals including lead and cadmium.
What should someone with asthma do?
Treat the main night and the following morning as hazardous in cities: indoors, windows closed. It is a legitimate reason not to be in a metro for that week.
Are fireworks part of the tradition?
Lamps are the traditional observance. Fireworks are a later addition, and they are the part causing the air-quality and injury problems, which is worth knowing when the festival is described by its lights.
What does the word Diwali mean?
Dīpāvalī, from dīpa, a lamp, and āvalī, a row or series. A row of lamps, which is literally what is placed along a wall or a step.
What should a visitor actually do?
Plan around the closures, accept the sweets, consider earplugs, and go out and look at the lamps, which are the festival at its best.
Five Days, Three Stories, Four Religions
Diwali is a festival of lamps lit on the darkest night of the month, which begins with cleaning a house and ends with rites between siblings, and which at least three different narratives claim to explain. Four religions observe the date for four unrelated reasons. The lamps are the tradition and the fireworks are an addition, and the addition is the part putting lead in the air, which an honest account says rather than leaving out.
Rohit Yoga Academy runs a residential 200-hour Yoga Teacher Training in Swargashram, Rishikesh, where courses running over Diwali mark the main night and explain what is being marked.