OCMA-Data is a comprehensive and structured Orthodox Christian liturgical calendar dataset. It provides machine-readable JSON files for each liturgical year, supporting both the Old Calendar (Julian) and the New Calendar (Revised Julian) for the years 1924–2099.

This repository serves as the canonical data source for the OCMA application, while remaining framework-agnostic and reusable for a wide range of applications and research projects.

• Fixed and movable feast cycles
• Complete Paschal cycle for each supported year
• Old Calendar (Julian) and New Calendar (Revised Julian) alignment

• Feasts: Great, Major, Minor and Lesser feasts
• Saints: Common Saints and additional local Saints
• Fasting Rules: Fasting seasons and daily fasting levels
• Lectionary:
  • Tone of the week
  • Sunday Matins Gospel, Epistle and Gospel

• Pascha date per year
• Primary lunar phases relevant to the liturgical calendar

OCMA-Data is designed to be fully translation-friendly.

• Supported languages:
  • English
  • Greek
  • Romanian
  • Russian

Each language is stored in separate JSON files, ensuring a strict separation between:

• Liturgical logic and calendar calculations
• Human-readable language content

This approach allows new languages to be added easily without modifying the core calendar data.

OCMA-Data follows a year-based, language-separated JSON structure:

• One JSON file per year, containing all liturgical days and data for that year
• One JSON file per language, holding translated textual content
• One unified Paschalion JSON file, covering Pascha dates for all supported years

This structure provides:

• Predictable file organization
• Efficient data loading for applications
• Clear separation of concerns between calendar logic and translations

The dataset is optimized for clarity, maintainability, and long-term extensibility.

OCMA-Data is suitable for:

• Developers building Orthodox calendar applications
• Researchers analyzing Orthodox liturgical cycles and calendar systems
• Church organizations requiring structured liturgical data
• Faithful seeking programmatic access to daily liturgical information

Contributions are welcome and encouraged.

You can help by:

• Adding new language translations
• Improving existing translations
• Correcting or enriching liturgical data
• Enhancing documentation

Please submit a pull request or open an issue to discuss proposed changes.

If you encounter bugs, data inconsistencies, or have suggestions for improvement, please open an issue on the GitHub tracker:

👉 https://github.com/ephmo/ocma-data/issues

Your feedback helps improve the quality and reliability of the dataset.

OCMA-Data is released under the MIT License.

See the LICENSE file for full details.