flutter utc to local date conversion example

main.dart

import 'package:flutter/material.dart';
import 'package:intl/intl.dart';
import 'package:timezone/data/latest.dart' as tz;
import 'package:timezone/timezone.dart' as tz;

void main() {
  tz.initializeTimeZones();
  runApp(const MyApp());
}

class MyApp extends StatelessWidget {
  const MyApp({Key? key}) : super(key: key);

  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      title: 'Date Converter',
      theme: ThemeData(
        primarySwatch: Colors.blue,
      ),
      home: const DateConverterPage(),
    );
  }
}

class DateConverterPage extends StatefulWidget {
  const DateConverterPage({Key? key}) : super(key: key);

  @override
  _DateConverterPageState createState() => _DateConverterPageState();
}

class _DateConverterPageState extends State<DateConverterPage> {
  final TextEditingController _dateController = TextEditingController();
  final TextEditingController _epochController = TextEditingController();
  final TextEditingController _timezoneController = TextEditingController();
  String _convertedDate = '';

  void _convertDateFromDateTimeString() {
    setState(() {
      final timezoneName = _timezoneController.text;
      final dateTimeString = _dateController.text;

      if (timezoneName.isNotEmpty && dateTimeString.isNotEmpty) {
        try {
          final location = tz.getLocation(timezoneName);
          final dateTime = DateTime.parse(dateTimeString);
          final convertedDateTime = tz.TZDateTime.from(dateTime, location);
          _convertedDate = DateFormat('yyyy-MM-dd HH:mm:ss').format(convertedDateTime);
        } catch (e) {
          _convertedDate = 'Invalid Date or Timezone';
        }
      } else {
        _convertedDate = 'Please enter date, time, and timezone';
      }
    });
  }

  void _convertDateFromEpoch() {
    setState(() {
      final timezoneName = _timezoneController.text;
      final epochString = _epochController.text;

      if (timezoneName.isNotEmpty && epochString.isNotEmpty) {
        try {
          final location = tz.getLocation(timezoneName);
          final epoch = int.parse(epochString);
          final dateTime = DateTime.fromMillisecondsSinceEpoch(epoch * 1000, isUtc: true);
          final convertedDateTime = tz.TZDateTime.from(dateTime, location);
          _convertedDate = DateFormat('yyyy-MM-dd HH:mm:ss').format(convertedDateTime);
        } catch (e) {
          _convertedDate = 'Invalid Epoch or Timezone';
        }
      } else {
        _convertedDate = 'Please enter epoch and timezone';
      }
    });
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: const Text('Date Converter'),
      ),
      body: Padding(
        padding: const EdgeInsets.all(16.0),
        child: Column(
          mainAxisAlignment: MainAxisAlignment.start,
          crossAxisAlignment: CrossAxisAlignment.stretch,
          children: <Widget>[
            TextField(
              controller: _dateController,
              decoration: const InputDecoration(
                border: OutlineInputBorder(),
                labelText: 'Enter Date & Time (yyyy-MM-ddTHH:mm:ssZ)',
              ),
            ),
            const SizedBox(height: 20),
            ElevatedButton(
              onPressed: _convertDateFromDateTimeString,
              child: const Text('Convert from Date/Time'),
            ),
            const SizedBox(height: 20),
            TextField(
              controller: _epochController,
              decoration: const InputDecoration(
                border: OutlineInputBorder(),
                labelText: 'Enter Epoch Time (seconds)',
              ),
            ),
            const SizedBox(height: 20),
            ElevatedButton(
              onPressed: _convertDateFromEpoch,
              child: const Text('Convert from Epoch'),
            ),
            const SizedBox(height: 20),
            TextField(
              controller: _timezoneController,
              decoration: const InputDecoration(
                border: OutlineInputBorder(),
                labelText: 'Enter Timezone (e.g., Asia/Dhaka)',
              ),
            ),
            const SizedBox(height: 20),
            Text(
              'Converted Date: $_convertedDate',
              style: const TextStyle(fontSize: 18),
            ),
          ],
        ),
      ),
    );
  }
}