Universal Calendar OS

The open astronomical engine and methodology platform for every calendar and fortune-telling tradition on Earth. One API. Every tradition. Deterministic calculations.

Browse Methodologies API
19
Methodologies
5
Calendar Systems
27
Nakshatras
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TODAY — Thursday, March 26, 2026

First Quarter

ข้างขึ้น (ครึ่งดวง)
51.9%
Illumination
7.6
Days old
97.5°
Moon Long.
วันพฤหัสบดี ขึ้น 9 ค่ำ เดือน 4 ปีเถาะ จ.ศ. 1387

What is Calenos?

Android is to phones what Calenos is to fortune-telling calendars. The core engine computes astronomical data once, and every tradition uses it.

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Astronomical Engine

Jean Meeus moon phase calculations, sun/moon longitude, Julian Date conversions. Accurate to ±0.01 day. The bedrock for all traditions.

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Methodology DSL

Fortune-telling calculations encoded as JSON — not code. Deterministic, auditable, portable. Anyone can create and share methodologies.

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Plugin Architecture

5 calendar systems built-in: Thai, Lanna, Chinese, Hijri, Hebrew. Add more by implementing one PHP interface.

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Multi-Tradition

One API call returns Thai riksa + Chinese zodiac + Hijri date + Hebrew calendar. Cross-tradition analysis in seconds.

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Fast & Free

All core calculations are algorithmic — no database required. Sub-10ms execution. Free tier with generous API limits.

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Open Format

Methodology JSON schema is open. Build your own tools, create your own methodologies, audit every calculation step.

Supported Traditions

🇹🇭 Thai โหราศาสตร์ 🏔️ Lanna ล้านนา 🇨🇳 Chinese 农历 ☪️ Islamic Hijri ✡️ Hebrew Calendar 🇮🇳 Vedic (coming) ♈ Western (coming) 🇯🇵 Japanese (coming) 🇲🇲 Burmese (coming)

One API.
Every Tradition.

Execute any methodology with a single API call. Get structured results with scores, labels, and display hints — ready for your UI.

Read the Docs
// Execute Thai Riksa methodology GET /api/v2/execute/thai-riksa/2026-03-26 // Response { "ok": true, "data": { "methodology": "thai-riksa", "result": { "primary": { "label": "ฤกษ์", "value": "ราชาฤกษ์", "subtitle": "ดี" }, "score": { "value": 4, "max": 5 } } } }