CRONUS 🕰️

A Beautiful, Multilingual Cron Expression Editor with Real-time Visualization

CRONUS is a powerful, user-friendly web application for creating, editing, and visualizing cron expressions. Whether you're a system administrator, developer, or anyone working with scheduled tasks, CRONUS makes cron expressions intuitive and accessible.

✨ Features

🌍 Multilingual Support

• Japanese (日本語) - Complete localization for Japanese users
• English - Full English language support
• Automatic language switching based on timezone selection

🌐 Timezone-Aware

• Support for multiple timezones including UTC, JST, EST, PST, and more
• Real-time conversion of execution times to selected timezone
• Intelligent timezone-language mapping

🎨 Beautiful, Modern UI

• Clean, gradient-based design with glassmorphism effects
• Responsive layout that works on desktop, tablet, and mobile
• Real-time visual feedback with color-coded validation
• Smooth animations and transitions

⚡ Powerful Functionality

• Real-time validation - Instant feedback on cron expression validity
• Human-readable descriptions - Converts complex cron syntax to natural language
• Next execution preview - Shows the next 3 scheduled execution times
• Visual cron builder - Interactive visualization of each cron field
• Common expressions - Pre-built templates for frequent use cases
• URL sharing - Share cron expressions via URL parameters

🛠️ Developer-Friendly

• Built with modern Next.js 15 and React 19
• Full TypeScript support for type safety
• Optimized with Turbopack for lightning-fast development
• Clean, maintainable code architecture

🚀 Quick Start

Prerequisites

• Node.js 22+
• npm, yarn, pnpm, or bun

Installation

# Clone the repository
git clone https://github.com/hatsu38/cronus.git
cd cronus

# Install dependencies
npm install
# or
yarn install
# or
pnpm install

Development

# Start the development server
npm run dev
# or
yarn dev
# or
pnpm dev
# or
bun dev

Open http://localhost:3000 in your browser to see the application.

📖 How to Use

Basic Usage

1. Enter your cron expression in the input field
2. Select your preferred timezone
3. View the human-readable description and next execution times
4. Use the visual cron builder to understand each field

Common Expressions

CRONUS includes pre-built templates for common scheduling patterns:

• Every minute: * * * * *
• Every hour: 0 * * * *
• Daily at midnight: 0 0 * * *
• Weekly on Sundays: 0 0 * * 0
• Monthly on the 1st: 0 0 1 * *
• And many more...

URL Sharing

Share your cron expressions by copying the URL, which automatically includes:

• The cron expression
• Selected timezone
• All settings are preserved when the link is opened

🏗️ Project Structure

cronus/
├── src/
│   ├── app/                 # Next.js app router
│   ├── components/          # React components
│   │   └── CronEditor.tsx   # Main editor component
│   └── lib/                 # Utility libraries
│       ├── cron.ts          # Cron parsing and validation
│       ├── cronI18n.ts      # Internationalization for cron
│       └── i18n.ts          # i18next configuration
├── public/                  # Static assets
└── package.json

🛠️ Built With

• Next.js 15 - React framework with App Router
• React 19 - UI library with latest features
• TypeScript - Type-safe JavaScript
• Tailwind CSS 4 - Utility-first CSS framework
• i18next - Internationalization framework
• cron-parser - Cron expression parsing
• date-fns - Modern JavaScript date utility library

📱 Screenshots

Desktop View

The main interface showcases a clean, modern design with real-time validation and timezone-aware execution times.

Mobile Responsive

Fully responsive design that adapts beautifully to mobile devices while maintaining full functionality.

🌟 Use Cases

For Developers

• CI/CD Pipelines - Schedule automated builds and deployments
• Database Maintenance - Set up regular backup and cleanup tasks
• Monitoring - Schedule health checks and system monitoring
• Data Processing - Automate ETL processes and data synchronization

For System Administrators

• Server Maintenance - Schedule system updates and restarts
• Log Rotation - Automate log file management
• Backup Systems - Set up automated backup schedules
• Resource Monitoring - Schedule performance and resource checks

For Content Managers

• Content Publishing - Schedule blog posts and content updates
• Email Campaigns - Automate newsletter and marketing emails
• Social Media - Schedule social media posts
• Report Generation - Automate regular reporting tasks

🔧 Scripts

npm run dev          # Start development server with Turbopack
npm run build        # Build for production
npm run start        # Start production server
npm run lint         # Run ESLint
npm run format:check # Check code formatting
npm run format:fix   # Fix code formatting

🤝 Contributing

We welcome contributions! Here's how you can help:

1. Fork the repository
2. Create a feature branch (git checkout -b feature/amazing-feature)
3. Commit your changes (git commit -m 'Add amazing feature')
4. Push to the branch (git push origin feature/amazing-feature)
5. Open a Pull Request

Development Guidelines

• Follow the existing code style
• Add tests for new features
• Update documentation as needed
• Ensure all tests pass before submitting

📝 License

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

🙏 Acknowledgments

• cron-parser community for the excellent parsing library
• Next.js team for the amazing framework
• Tailwind CSS for the beautiful utility classes
• i18next for internationalization capabilities

📞 Support

If you encounter any issues or have questions:

1. Check the Issues page
2. Create a new issue with detailed information
3. Join our community discussions

🌐 Help with Internationalization

We're looking for contributors to help expand CRONUS to more languages! Currently supporting Japanese and English, we'd love to add support for:

• Korean (한국어)
• Chinese Simplified (简体中文)
• Chinese Traditional (繁體中文)
• Spanish (Español)
• French (Français)
• German (Deutsch)
• Portuguese (Português)
• Russian (Русский)
• Italian (Italiano)
• Dutch (Nederlands)

How you can help:

• Translate UI text and descriptions
• Review existing translations for accuracy
• Add timezone and date formatting for your locale
• Test the application with your language

If you're interested in helping with translations, please:

1. Open an issue mentioning the language you'd like to contribute
2. Check our internationalization guide for the translation structure
3. We'll provide you with the necessary translation keys and guidance

Translation Contributors Welcome! 🙏
No programming experience required - just native language skills and attention to detail.

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Made with ❤️ by hatsu38

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