💡 Introduction

In today’s student life, accessing your timetable quickly and accurately is crucial. Many of us struggle with messy Excel sheets, confusing subject codes, or big PDFs. To solve this, I designed a Personalized Timetable Tool that shows exactly what each student has, based on their selected subjects — lightweight, mobile-friendly, and easy to access as a Progressive Web App (PWA).

🗄️ Backend: Database Structure and Logic

👤 Students Table

I started with a students table that stores:

• roll_no (student roll number)

• name

• Subject codes as columns (like 22CS1157, 22CS1104, etc.), where value 1 means opted and 0 means not opted.

This design allows us to dynamically determine which subjects each student has chosen.

📄 Subjects Mapping Table

We have a subjects table that maps:

• subject_name → subject_code

This ensures we can match names in the timetable JSON to codes in the student table.

🗓️ JSON-based Master Timetable

I prepared a master_timetable.json file that contains:

• Day-wise slots

• Subjects possible in each slot

• Corresponding room numbers

Each slot also contains an array of rooms, which matches the subjects list.

⚙️ Backend Script: get_timetable.php

When a student logs in and selects a day:

1. We load their roll number from the session.

2. We load master_timetable.json and filter slots for that day.

3. We fetch the student’s subject selections from the DB.

4. For each slot, we check:

   • If the student opted for any subject in that slot.

   • If no subject matched, we mark it as 🎉.

   • Lunch and "Honors / Minors" slots are handled separately.

5. We prepare a personalized JSON response with time, subject, and room.

🖥️ Frontend: fetch.php

Once logged in, students land on a stylish dark-themed dashboard.

Key features:

• Shows student’s name (fetched from DB).

• Day selector dropdown.

• "Check Today's" button (auto-selects today’s day using Asia/Kolkata timezone).

• Logout button.

When a day is selected:

• A loader (spinner) fades in, blocking until data loads.

• Personalized timetable is displayed in a dark-themed table with white text.

• Room information is included with each subject.

📲 Progressive Web App (PWA) Support

Manifest & Icons

• I added a manifest.json containing app metadata, icons (192x192, 512x512), theme colors, etc.

• Ensures it appears as a real app when added to home screen.

🔥 FCM Push Notifications with Cron

Each student’s FCM token is stored when they log in (via save_fcm_token.php).

The cron job:

• Runs every 5 minutes automatically.

• Checks the master timetable JSON to see if any slot starts in the next 5 minutes (Asia/Kolkata timezone).

• For each student:

  • Finds if they have opted for a subject in that slot.

  • Ignores Lunch or Honors/Minors slots.

  • Sends a high-priority push notification with subject and room number.

• Uses Firebase Cloud Messaging v1 API, secured with access tokens.

🔐 Access Token Handling (Vendor & Composer)

We use the Firebase Admin SDK, installed via Composer (vendor folder in /csm/push/).

Our access_token.php:

• Generates a new access token from Firebase service account JSON.

• Saves it into access_token.json.

• If expired, automatically refreshes the token on next cron run.

Ensures notifications are always authenticated securely.

⚙️ Cron Job (Server-Side Automation)

A PHP cron script runs every 5 minutes on the server.

No manual intervention needed — it auto-checks current time and slots, sends notifications to each student.

Service Worker

We created a basic service-worker.js that enables install prompts and future caching (if needed).

Add to Home Screen

• A custom "Add to Home Screen" button is shown only if not already installed.

• Uses beforeinstallprompt event to trigger native prompt.

• Hides button automatically if the app is already running in standalone mode.

🔐 Authentication

• Login using roll number.

• Roll number is stored in PHP session to keep students logged in.

• Secure backend checks prevent access if not logged in.

• A dedicated Logout button destroys the session and redirects to home.

🌟 User Experience Polishing

• Good accent colors for headings and labels.

• "Made with ❤️ by R Viswath" footer, linking to my personal website.

• Clean, compact layout that feels like a native app.

• Smooth fade-in of loader and tables for an elegant touch.

💬 Final Thoughts

This tool:
✅ Removes need for heavy Excel sheets.
✅ Automatically filters subjects based on student selections.
✅ Works seamlessly on mobile, and can be added as an app.
✅ Is fast, beautiful, and personalized!

🔗 Try It Out

👉 Check it out here

✉️ Have feedback or want to build your own?

Feel free to reach out via viswath.me 💬

✨ Bonus: How "auto run" works (cron job magic)

The magic behind automated push reminders:

• Cron job runs automatically every 5 minutes — no need for you or students to open the site.

• Uses timezone-aware logic to check slots.

• Your server handles all logic and fires notifications in the background.

🎁 Conclusion

With this project, we've blended PHP, Ajax, MySQL, JSON, Bootstrap, jQuery, and PWA standards into a single, modern student tool. Not only is it technically robust, it is designed with care to simplify everyday life for students.