Lunar Calendar

Lunar Calendar is an open-source application that provides a clear daily snapshot of the Moon and Sun. It delivers lunar phases and positional data in a clean, developer-friendly interface designed for both learning and integration.

The application retrieves ephemeris data directly from the NASA Jet Propulsion Laboratory Horizons system via https://ssd.jpl.nasa.gov/api/horizons.api, ensuring scientifically reliable Sun and Moon positions, angles, and distances.

Key highlights:

• Daily lunar and solar snapshot
• Clear presentation of moon phase, sky basics, and spatial positions
• Open source codebase designed for extensibility and trust
• Simple UI focused on clarity, engagement, and usability

API

You can try out the API live at: https://lunar-calendar-laeb.onrender.com/docs

• It is using the free render service; wait for a few minutes if it's not active.
• Rate limit: 60 requests per minute per IP.

Technical Implementation

• NASA Horizons API integration and response parsing
• TTL-based caching to optimize performance
• Database persistence for computed results
• Per-IP rate limiting for fair usage
• Robust error handling and input validation
• Client-side caching using localStorage with eviction policy
• Graceful handling of network failures and invalid responses
• UTC-based date validation and defaults
• Extensible support for multi-planet ephemeris and visualization

Read

• https://en.wikipedia.org/wiki/Tithi
• https://www.quora.com/What-is-the-difference-between-a-tithi-and-a-day-according-to-the-Hindu-calendar
• https://ssd-api.jpl.nasa.gov/doc/horizons.html