---
title: "Regional calendar: convert a Gregorian date"
method: POST
path: "/vedic/calendar/regional/date"
tags: ["Vedic"]
---

# Regional calendar: convert a Gregorian date

`POST /vedic/calendar/regional/date`

## Request

- Base URL: `https://api.astroway.info/v1`
- URL: `https://api.astroway.info/v1/vedic/calendar/regional/date`
- Auth: API key in header `X-Api-Key`
- TypeScript: <https://skmtc.dev/astroway/apis/astroway-calculation-api/docs/vedic/calendar/regional/date/post.ts> (a function with typed inputs; its response is checked against the schema)

One Gregorian date in a regional calendar at the place. Solar calendars (tamil, malayalam, bengali): month, its number, day of the month and the era year. Lunisolar (gujarati, marathi): amanta month, the tithi at local sunrise with its paksha (Sud and Vad for Gujarati), adhika flag and the era year. Each answer carries the month's first and last civil day and the rule used.

## Query parameters

- `fields` string
- `precision` integer

## Headers

- `Idempotency-Key` string

## Request body

- RegionalDateInput: A regional calendar, a Gregorian date and a place.
  - `calendar` 'tamil' | 'malayalam' | 'bengali' | 'gujarati' | 'marathi', required: tamil, malayalam, bengali (solar months from the sankranti by each region's rule), gujarati (amanta, Vikram Samvat from Kartika), marathi (amanta, Shaka from Chaitra).
  - `date` string, required: Gregorian date, YYYY-MM-DD, local to the place.
  - `latitude` number, nullable, required: 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, nullable, required: Longitude in decimal degrees, east positive.
  - `timezone` string: 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, nullable: A fixed offset in hours instead of a zone, for the whole year. Ignored when timezone is sent.
  - `ayanamsaId` number, nullable
  - `ayanamsa` 'fagan-bradley' | 'lahiri' | 'de-luce' | 'raman' | 'krishnamurti' | 'kp' | 'yukteshwar' | 'jn-bhasin' | 'true-citra' | 'djwhal-khul': Sidereal school by name. Lahiri when omitted. Equivalent to ayanamsaId; send either.

## Response `200`

Successful calculation

- object
  - `ok` boolean
  - `data` object
    - `calendar` string, nullable
    - `date` string, nullable
    - `month` string, nullable
    - `monthNumber` number, nullable
    - `day` number, nullable
    - `tithi` unknown
    - `adhika` boolean, nullable
    - `year` object, nullable
      - `era` string, nullable
      - `number` number, nullable
      - `name` unknown
    - `monthStart` string, nullable
    - `monthEnd` string, nullable
    - `rule` string, nullable
    - `place` object, nullable
      - `latitude` number, nullable
      - `longitude` number, nullable
      - `timezone` string, nullable
      - `timezoneOffset` unknown
      - `ayanamsaId` number, nullable

## Other responses

- `400`: Validation error
- `401`: Missing or invalid API key

## Changes

- **2026-11-07** `69a55e116a5e`: 1 info
  - endpoint added

[Operation history](https://skmtc.dev/astroway/apis/astroway-calculation-api/changes/vedic/calendar/regional/date/post.md)

---

[API](https://skmtc.dev/astroway/apis/astroway-calculation-api.md) - [All operations](https://skmtc.dev/astroway/apis/astroway-calculation-api/llms.txt) - [OpenAPI document](https://skmtc.dev/astroway/apis/astroway-calculation-api/revisions/bf266b2e6703?raw)