# Hindu calendar: festivals for a year and place

`POST https://api.astroway.info/v1/vedic/calendar/festivals`

About 55 pan-Indian festivals dated for the place: Makar Sankranti, Maha Shivaratri, Holika Dahan and Holi, Ugadi, Rama Navami, Hanuman Jayanti, Akshaya Tritiya, Guru Purnima, Raksha Bandhan, Janmashtami, Ganesh Chaturthi, Navratri, Dussehra, Karva Chauth, Dhanteras, Diwali, Govardhan Puja, Bhai Dooj, Chhath, Onam, Puthandu, Vishu, Pohela Boishakh and more. Each entry carries the rule that defines it (month, tithi and the kala it must hold at: sunrise, madhyahna, aparahna, pradosha, nishita, moonrise), the source, how the day was decided (`basis`: vyapti on one day, vriddhi on two and the tie-break, kshaya on none), the tithi with its local start and end, the amanta and purnimanta month and the kala window. `tradition`: smarta (default) or vaishnava where they differ (Rama Navami, Janmashtami). `timezone` (IANA or auto) is followed day by day, summer time included. Checked against drikpanchang for New Delhi, Chennai and New York 2025 and 2026: 323 of 325 dates.

Group: Vedic. Auth: `X-Api-Key` header. Operation ID: `vedic_calendar_festivals`.

## Parameters

| Name | In | Required | Type | Description |
|---|---|---|---|---|
| `fields` | query | no | string | Comma-separated dotted paths, relative to `data`, to keep in the response. A path is applied to every element of an array, so `planets.name` means the name of each planet. Paths that match nothing come back in `_fields_unmatched`; a list where nothing matches at all is a 400, because an empty object would be a confident wrong answer. |
| `precision` | query | no | integer | Round every non-integer number in the response to this many decimal places. Integers are left alone, because an id is not a measurement. Ecliptic longitudes ship with fourteen decimals by default; 2 is about a tenth of an arcminute. |
| `Idempotency-Key` | header | no | string | Unique per logical operation, kept across retries. For 24 hours from the first request, a repeat with the same key, method, path, body and query string returns the stored response with `Idempotent-Replayed: true` and costs 0 credits. The same key with a different body or query string is a 409 `IDEMPOTENCY_KEY_REUSED`; a repeat while the first is still running is a 409 `IDEMPOTENCY_IN_PROGRESS`. Only 2xx responses are kept. See /idempotency/. |

## Request body

| Field | Type | Required | Description |
|---|---|---|---|
| `year` | integer | yes | Gregorian year, 1900 to 2100. Entries are those whose date falls in this year. |
| `latitude` | number | yes | Latitude in decimal degrees, north positive. Between -66 and 66: further out the Sun does not rise on some days and a Hindu day has no start. |
| `longitude` | number | yes | Longitude in decimal degrees, east positive. |
| `timezone` | string | no | IANA zone name such as Asia/Kolkata, America/New_York or Europe/Kyiv, or auto (default) to look it up from the coordinates. Resolved day by day: each day is read on the offset that zone kept that day, so summer time is followed. |
| `timezoneOffset` | number | no | A fixed offset in hours instead of a zone, for the whole year. Ignored when timezone is sent. |
| `ayanamsaId` | number | no |  |
| `ayanamsa` | "fagan-bradley" \| "lahiri" \| "de-luce" \| "raman" \| "krishnamurti" \| "kp" \| "yukteshwar" \| "jn-bhasin" \| … | no | Sidereal school by name. Lahiri when omitted. Equivalent to ayanamsaId; send either. |
| `tradition` | "smarta" \| "vaishnava" | no | Whose reckoning decides the day where they differ (Rama Navami, Janmashtami). smarta (default): the tithi at the rite's kala, as Dharmasindhu gives it; vaishnava: the ISKCON rule, the tithi at sunrise unmixed with the one before. |
| `festivals` | "makar-sankranti" \| "pongal" \| "vasant-panchami" \| "ratha-saptami" \| "bhishma-ashtami" \| "maha-shivaratri" \| "holika-dahan" \| "holi" \| …[] | no | Only these festival ids. All when omitted. |

```json
{
  "year": 2026,
  "latitude": 28.6139,
  "longitude": 77.209,
  "timezone": "Asia/Kolkata",
  "festivals": [
    "diwali",
    "makar-sankranti"
  ]
}
```

## Responses

| Status | Meaning |
|---|---|
| 200 | Successful calculation |
| 400 | Validation error |
| 401 | Missing or invalid API key |

### Success fields, under `data`

| Field | Type | Required | Description |
|---|---|---|---|
| `year` | number | no |  |
| `place` | object | no |  |
| `place.latitude` | number | no |  |
| `place.longitude` | number | no |  |
| `place.timezone` | string | no |  |
| `place.timezoneOffset` | object | no |  |
| `place.ayanamsaId` | number | no |  |
| `tradition` | string | no |  |
| `count` | number | no |  |
| `festivals` | object[] | no |  |
| `conventions` | object | no |  |
| `conventions.day` | string | no |  |
| `conventions.kalas` | string | no |  |
| `conventions.months` | string | no |  |

## Example

```bash
curl -X POST https://api.astroway.info/v1/vedic/calendar/festivals \
  -H "X-Api-Key: aw_live_..." \
  -H "Content-Type: application/json" \
  -d '{ "year": 2026, "latitude": 28.6139, "longitude": 77.209, "timezone": "Asia/Kolkata", "festivals": [ "diwali", "makar-sankranti" ] }'
```

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Rendered from https://api.astroway.info/v1/openapi.json. HTML page: https://api.astroway.info/docs/api/operations/vedic_calendar_festivals/