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Lang2Cron - Natural Language to UNIX Cron Generator

A lightweight, zero-backend single-page web application that converts natural language schedule requests into standard 5-field UNIX cron expressions using Google Gemini for grounding, interactive clarification, and multilingual understanding.

Open Lang2Cron Application

Overview

Writing and debugging cron syntax often leads to mistakes or platform discrepancies—especially around 5-field UNIX conventions versus 6-field quartz variants, or day-of-week indexing (where 0 represents Sunday).

Lang2Cron provides an intuitive conversational interface where functional users, sysadmins, and developers can describe when a recurring job should execute in plain words. Lang2Cron clarifies ambiguities and validates the resulting schedule against standard UNIX cron rules directly in the browser.

Key Features

1. Conversational Grounding & Clarification

• Handles Ambiguous Input: If a user enters vague statements like "I want to run it recurrently" or "run it often", the grounding model proactively asks clarifying questions ("When do you need to run it? Daily, every 2 days? At what time?") until a deterministic schedule is achieved.
• Multilingual Support: Users can enter schedule requests in English, Spanish, French, German, Italian, Portuguese, and more.
• Self-Documenting Grounded Help: Asking questions such as "How do I use you?" or "¿Cómo te uso?" triggers an in-context explanation of how to use the converter.

2. Standard 5-Field UNIX Cron Compliance

Enforces strict 5-field UNIX syntax:

┌───────────── Minute (0 - 59)
│ ┌─────────── Hour (0 - 23)
│ │ ┌───────── Day of Month (1 - 31)
│ │ │ ┌─────── Month (1 - 12)
│ │ │ │ ┌───── Day of Week (0 - 6) (0 = Sunday)
│ │ │ │ │
* * * * *

• Restricts operators strictly to * (every), */n (step), , (list), and - (range).
• Rejects non-standard quartz seconds fields, L, W, ?, or # flags to prevent execution surprises across heterogeneous Linux/UNIX environments.

3. Client-Side Validation & Compilation

• The Gemini model produces a structured grounding spec.
• A client-side JavaScript engine verifies field limits (0–59, 0–23, 1–31, 1–12, 0–6), step bounds, and ranges before assembling the final pattern.
• Displays a prominent Field-by-Field Breakdown inspecting Minute, Hour, Day of Month, Month, and Day of Week tokens.

4. 1-Click Copy & Productivity

• Copy the generated cron expression instantly with visual feedback (Copied! ✓).
• Quick-starter example chips for common patterns ("Every 15 minutes", "Weekdays at 09:00 AM", "First day of month", etc.).

5. Dark & Light Mode

• Clean, responsive UI featuring both dark and light modes.
• Theme preference is remembered across sessions via localStorage.

6. Zero-Backend Privacy

• No backend servers, databases, or cookies.
• Your Gemini API key is stored strictly on your device in browser localStorage and sent directly to Google's Generative Language API endpoint.

Standard UNIX Cron Reference Table

System Clock Reminder: Standard UNIX cron schedules run relative to the host system clock (often configured to UTC). Ensure your server timezone aligns with your scheduled intent.

Usage Guide

1. Open Lang2Cron: Open lang2cron.html directly in any web browser or via GitHub Pages.
2. Configure Gemini API Key:
   • On first launch, enter your Gemini API key in the setup dialog.
   • You can update or remove the key at any time by clicking the Settings (⚙️) icon in the header.
3. Enter Your Schedule:
   • Type your requirement in the input box, such as "Run a backup every Sunday night at 11 PM" or click an example chip.
4. Clarify if Prompted:
   • If the request is incomplete, Lang2Cron will ask you for details (e.g. specific hour or weekdays).
5. Copy the Pattern:
   • Once resolved, click Copy Cron to copy the pattern to your clipboard.

Obtaining a Gemini API Key

Lang2Cron uses gemini-3.5-flash-lite, Google's lightweight and cost-effective Flash-tier model.

1. Go to Google AI Studio.
2. Sign in with your Google account.
3. Click Create API Key.
4. Copy the key, paste it into Lang2Cron, and click Save Key.

Technical Details

• Technology: Pure HTML5, CSS3, and vanilla JavaScript (no React, Vue, Angular, or Node.js).
• Model: gemini-3.5-flash-lite via https://generativelanguage.googleapis.com/v1beta/models/gemini-3.5-flash-lite:generateContent.
• Dependencies:
  • Tailwind CSS v2.2.19 (jsDelivr CDN with SHA-384 SRI)
  • Google Fonts Inter
• Compatibility: Runs directly via file:// protocol or static web hosting.

License

This project is licensed under the MIT License.

InnovUmabot | https://innovumabot.com

This tool was vibe-coded with AI with strict human supervision.