Why this platform exists
We are building the calendar infrastructure we wanted to integrate against and could not find.
The problem
Hindu calendar calculations sit underneath temple apps, matrimony platforms, festival calendars, payroll, travel, publishing and now AI assistants. Yet the APIs serving them return a date and nothing else. When the date is disputed — and it is disputed often, because these are questions communities care about — there is nothing to inspect.
What we changed
We rebuilt the festival engine around shastric kala-vyapini rules operating on real tithi intervals, rather than matching whatever tithi happened to be running at sunrise. Then we made the engine show its work: every festival carries the rule, the version, the authority, the overlap in minutes, and a confidence score.
Why it matters
A date you can audit is a date you can defend. An HR department can answer an employee. A temple committee can review a schedule. A newsroom can cite a source. An AI agent can ground an answer instead of inventing one.
What we will not do
We will not publish a number we have not measured, and we will not hide a limitation to look better. The Accuracy page lists our known problems because you are going to find them eventually, and it is better that you find them from us.
Roadmap
Now, next, and later
Items move between columns as they ship. Anything listed under Next has a named owner and a target release.
Now
Festival Engine V2 in production
Nine evaluators, tie-break, series resolution, rule versioning.
Explainability and observatory mode
Evaluation traces and raw astronomical facts on request.
Webhook platform
HMAC-signed delivery with backoff and idempotency.
Verification framework
Tier A/B/C running against every build.
Next
Base engine auditv2.1.0
Determine precisely how tithi, nakshatra, yoga and karana are computed in the legacy path — ephemeris versus approximation. Gates the remaining astronomy fixes.
Sankranti precisionv2.1.0
Replace the 1.5° threshold with a binary search on Swiss Ephemeris for the exact sign-change instant.
Disha Shool correctionv2.1.0
Reindex the weekday map. A one-line fix, listed here because it is currently wrong.
CSP nonce migrationv2.1.0
Remove unsafe-inline from script-src and style-src to close PCI DSS 6.4.
Multi-location materialisationv2.2.0
Extend the nightly job beyond location 1 to the top five locations.
Regional rule packsv2.2.0
Author Tamil, Gujarati and ISKCON packs. The engine already supports them; the data does not exist yet.
Later
MCP server
Expose the API as tools for agent frameworks directly.
Additional SDKs
Go, PHP and Dart clients generated from the same spec.
Merged application
Combine the two FastAPI applications into one with modular routers.
Read replica
Separate read capacity for the panchang tables.
CI/CD pipeline
Tests on pull request, verification nightly, automated deploy on merge.