Hindu calendar API · in early access
The Hindu calendar API that is correct in your users' timezone, and proves it.
TithiKit is a planned panchang API for apps and websites that serve Hindu families outside India: lunar days, months and festival dates computed for the user's own city and timezone, with the rule behind every date. The API is being built now. Join early access to get a free key when it opens.
What makes it different
Four commitments, in priority order.
Any city, any timezone
Each day is built from local sunrise at the user's own coordinates, in their IANA timezone, with daylight-saving gaps and overlaps handled. Not India's dates copied abroad.
Rules you can show your users
Every response is planned to carry rules_applied: the named rule behind each festival date, plus the ayanamsa, sunrise definition, engine and tzdb versions used.
Accuracy you can check
A public, versioned test suite against hand-transcribed printed almanacs and an independent ephemeris. Failures are published, not hidden.
Built for developers abroad
Planned: USD pricing with a free tier, an OpenAPI 3.1 spec, TypeScript and Python SDKs, ICS feeds and an MCP server for AI agents.
Where Hindu calendar code usually breaks
These are the cases the engine and its public test suite are designed around.
| Case | Why it matters |
|---|---|
| A tithi that ends overnight | The tithi of the day is the one in effect at local sunrise. A transition at 01:30 in New York and 11:00 in Delhi lands on different sides of sunrise. |
| Daylight saving time | A local hour is skipped in spring and repeated in autumn. Fixed UTC offsets put transition times an hour out for half the year. |
| Skipped and repeated tithis | Some tithis never touch a sunrise and are skipped; others span two sunrises and repeat. Naive day-by-day code misses both. |
| Leap months | When a lunar month contains no solar ingress (sankranti), it becomes an adhika (extra) month, shifting festival month names. |
| Regional month systems | Telugu, Kannada, Marathi and Gujarati calendars end months at the new moon; most of North India ends them at the full moon. |
| No sunrise at all | Above the Arctic Circle the Sun may not rise or set for weeks. Code that assumes a sunrise every day fails silently. |
How it will work
Three inputs, one response with the reasoning attached.
- 1
Send a place and a date
Latitude, longitude, an IANA timezone such as America/Chicago, and the regional calendar you need. - 2
We compute local sunrise
The engine finds sunrise for that location and reads which lunar day, month and other elements are in effect then, and when they change. - 3
You get dates with reasons
Transition times in local time, festival dates with their named rule, and the versions used, so you can explain any date to your users.
The full walkthrough is on how it works. The planned response fields are described there; we will publish API documentation only once the endpoints are live.
Calendar data, nothing personal
TithiKit computes calendar and astronomical data for places and days. It never asks for anyone's birth details and stores no personal data from API calls. That keeps the data your app sends simple to protect. Read why we designed it this way.
Get a free API key at launch
Early-access members get the first keys, a launch email, and a say in which regional calendars we verify next.