feat: add a "Deadline Countdown" and calendar reminder feature to program detail screens — users currently see application dates as static text but have no way to track upcoming deadlines or add them to their device calendar

[divyanshim27]

🚀 Problem Statement

Open-source programs like GSoC, LFX, and Outreachy have strict application deadlines that students frequently miss. OpSo shows dates as static text on program detail screens, but:

1. There is no visual countdown showing "Application closes in 12 days"
2. There is no way to add a deadline reminder to the device calendar
3. There is no in-app notification system for upcoming deadlines
4. Missed deadlines = missed opportunities — this is exactly the problem OpSo should solve

For an app whose purpose is helping developers discover and apply to programs, deadline awareness is the single most impactful missing feature.

✅ Proposed Solution

1. Create a DeadlineCountdown widget

// lib/components/deadline_countdown.dart
import 'package:flutter/material.dart';
import 'dart:async';

class DeadlineCountdown extends StatefulWidget {
  final DateTime deadline;
  final String label;

  const DeadlineCountdown({Key? key, required this.deadline, required this.label})
      : super(key: key);

  @override
  State<DeadlineCountdown> createState() => _DeadlineCountdownState();
}

class _DeadlineCountdownState extends State<DeadlineCountdown> {
  late Timer _timer;
  late Duration _remaining;

  @override
  void initState() {
    super.initState();
    _remaining = widget.deadline.difference(DateTime.now());
    _timer = Timer.periodic(const Duration(seconds: 1), (_) {
      setState(() {
        _remaining = widget.deadline.difference(DateTime.now());
      });
    });
  }

  @override
  void dispose() { _timer.cancel(); super.dispose(); }

  Color get urgencyColor {
    if (_remaining.inDays < 3) return Colors.red;
    if (_remaining.inDays < 7) return Colors.orange;
    return Colors.green;
  }

  @override
  Widget build(BuildContext context) {
    if (_remaining.isNegative) {
      return Chip(
        label: const Text('Deadline Passed'),
        backgroundColor: Colors.grey[300],
      );
    }

    return Container(
      padding: const EdgeInsets.all(12),
      decoration: BoxDecoration(
        color: urgencyColor.withOpacity(0.1),
        border: Border.all(color: urgencyColor),
        borderRadius: BorderRadius.circular(8),
      ),
      child: Row(children: [
        Icon(Icons.timer, color: urgencyColor),
        const SizedBox(width: 8),
        Text(
          '${_remaining.inDays}d ${_remaining.inHours % 24}h ${_remaining.inMinutes % 60}m',
          style: TextStyle(color: urgencyColor, fontWeight: FontWeight.bold, fontSize: 18),
        ),
        const Spacer(),
        Text(widget.label, style: TextStyle(color: urgencyColor)),
      ]),
    );
  }
}

2. Add "Add to Calendar" button using add_2_calendar package

# pubspec.yaml
dependencies:
  add_2_calendar: ^3.0.1

// lib/components/add_to_calendar_button.dart
import 'package:add_2_calendar/add_2_calendar.dart';

void addDeadlineToCalendar({
  required String programName,
  required DateTime deadline,
  required String description,
}) {
  final Event event = Event(
    title: '$programName — Application Deadline',
    description: description,
    location: 'Online',
    startDate: deadline.subtract(const Duration(hours: 1)),
    endDate: deadline,
    allDay: false,
  );
  Add2Calendar.addEvent2Cal(event);
}

3. Integrate into program detail screens

// In each program's detail screen
Column(children: [
  DeadlineCountdown(
    deadline: program.applicationDeadline,
    label: 'Applications Close',
  ),
  const SizedBox(height: 8),
  ElevatedButton.icon(
    icon: const Icon(Icons.calendar_today),
    label: const Text('Add Reminder to Calendar'),
    onPressed: () => addDeadlineToCalendar(
      programName: program.name,
      deadline: program.applicationDeadline,
      description: 'Apply at: ${program.website}',
    ),
  ),
])

📁 Files to Modify

File	Change
pubspec.yaml	Add add_2_calendar dependency
lib/components/deadline_countdown.dart	Create animated countdown widget
lib/components/add_to_calendar_button.dart	Create calendar integration button
All program detail screens in lib/screens/	Integrate deadline + calendar button

Suggested labels: enhancement, flutter, ux, feature, level: beginner

I would like to work on this. Could you please assign it to me?

[github-actions]

Thank you for creating this issue! We'll look into it as soon as possible. Your contributions are highly appreciated! 😊

[divyanshim27]

Hey @andoriyaprashant ,
Please assign it to me under GSSoC 2026.
/claim /assign /claim-assignment