apiverve/julianday

Julian Day Calculator converts between Gregorian calendar dates and Julian Day Numbers (JDN). Julian Day is a continuous count of days used in astronomy and historical research.

dev-main 2026-07-16 20:37 UTC

Requires

• php: >=7.4
• guzzlehttp/guzzle: ^7.0

Requires (Dev)

• phpunit/phpunit: ^9.0

MIT

• APIVerve

• api
• calendar
• astronomy
• julian day
• JDN
• Julian Date
• apiverve
• julianday

Published on Packagist.org on 2026-07-16 20:46 UTC

README

Julian Day Calculator converts between Gregorian calendar dates and Julian Day Numbers (JDN). Julian Day is a continuous count of days used in astronomy and historical research.

The Julian Day Calculator API provides a simple, reliable way to integrate julian day calculator functionality into your applications. Built for developers who need production-ready julian day calculator capabilities without the complexity of building from scratch.

View API Details →

Available on:

Quick Start

Using JavaScript

async function callJulianDayCalculatorAPI() {
    try {
        const params = new URLSearchParams({
            date: '2024-03-15'
        });

        const response = await fetch(`https://api.apiverve.com/v1/julianday?${params}`, {
            method: 'GET',
            headers: {
                'x-api-key': 'YOUR_API_KEY_HERE'
            }
        });

        const data = await response.json();
        console.log(data);
    } catch (error) {
        console.error('Error:', error);
    }
}

callJulianDayCalculatorAPI();

Using cURL

curl -X GET "https://api.apiverve.com/v1/julianday?date=2024-03-15" \
  -H "x-api-key: YOUR_API_KEY_HERE"

Get your API key: https://apiverve.com

📁 For more examples, see the examples folder

Installation

Choose your preferred programming language:

📦 NPM (JavaScript/Node.js)

npm install @apiverve/julianday

View NPM Package → | Package Code →

🔷 NuGet (.NET/C#)

dotnet add package APIVerve.API.JulianDayCalculator

View NuGet Package → | Package Code →

🐍 Python (PyPI)

pip install apiverve-julianday

View PyPI Package → | Package Code →

💎 Ruby (RubyGems)

gem install apiverve_julianday

View RubyGems Package → | Package Code →

🐘 PHP (Packagist)

composer require apiverve/julianday

View Packagist Package → | Package Code →

🎯 Dart (pub.dev)

dart pub add apiverve_julianday

View pub.dev Package → | Package Code →

🤖 Android (JitPack)

implementation 'com.github.apiverve:julianday-api:1.0.0'

Package Code →

🐹 Go

go get github.com/apiverve/julianday-api/go

Package Code →

Why Use This API?

Feature	Benefit
Multi-language SDKs	Native packages for JavaScript, Python, C#, Go, and Android
Simple Integration	Single API key authentication, consistent response format
Production Ready	99.9% uptime SLA, served from 24 global regions
Comprehensive Docs	Full examples, OpenAPI spec, and dedicated support

Documentation

• 🏠 API Home: Julian Day Calculator API
• 📚 API Reference: docs.apiverve.com/ref/julianday
• 📖 OpenAPI Spec: openapi.yaml
• 💡 Examples: examples/

What Can You Build?

The Julian Day Calculator API is commonly used for:

• Web Applications - Add julian day calculator features to your frontend or backend
• Mobile Apps - Native SDKs for Android development
• Automation - Integrate with n8n, Zapier, or custom workflows
• SaaS Products - Enhance your product with julian day calculator capabilities
• Data Pipelines - Process and analyze data at scale

API Reference

Authentication

All requests require an API key in the header:

x-api-key: YOUR_API_KEY_HERE

Get your API key: https://apiverve.com

Response Format

Every APIVerve endpoint returns the same envelope — check status, then read data:

{
  "status": "ok",
  "error": null,
  "data": { ... }
}

Example Response

A real response from the Julian Day Calculator API:

{
  "status": "ok",
  "error": null,
  "data": {
    "gregorian": "2024-03-15",
    "julianDayNumber": 2460385,
    "modifiedJulianDate": 60384.5,
    "dayOfWeek": "Friday",
    "weekNumber": 11,
    "dayOfYear": 75,
    "daysFromToday": -340
  }
}

Support & Community

• 🏠 API Home: Julian Day Calculator API
• 💬 Support: https://apiverve.com/contact
• 🐛 Issues: GitHub Issues
• 📖 Documentation: https://docs.apiverve.com
• 🌐 Website: https://apiverve.com

Contributing

We welcome contributions! Please see CONTRIBUTING.md for guidelines.

Security

For security concerns, please review our Security Policy.

License

This project is licensed under the MIT License - see the LICENSE file for details.

Acknowledgments

Built with ❤️ by APIVerve

Copyright © 2026 APIVerve. All rights reserved.