showTimePicker

import 'package:flutter/material.dart';

void main() {
  runApp(MyApp());
}

class MyApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      home: MyHomePage(),
    );
  }
}

class MyHomePage extends StatefulWidget {
  @override
  _MyHomePageState createState() => _MyHomePageState();
}

class _MyHomePageState extends State<MyHomePage> {
  TimeOfDay selectedTime = TimeOfDay.now();

  Future<void> _selectTime(BuildContext context) async {
    final TimeOfDay? picked = await showCustomTimePicker(
      context: context,
      initialTime: selectedTime,
    );
    if (picked != null && picked != selectedTime) {
      setState(() {
        selectedTime = picked;
      });
    }
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: Text('Time Picker Example'),
      ),
      body: Center(
        child: Column(
          mainAxisAlignment: MainAxisAlignment.center,
          children: <Widget>[
            Text(
              "${selectedTime.format(context)}",
              style: TextStyle(fontSize: 32),
            ),
            SizedBox(height: 20),
            ElevatedButton(
              onPressed: () => _selectTime(context),
              child: Text('Select Time'),
            ),
          ],
        ),
      ),
    );
  }
}

Future<TimeOfDay?> showCustomTimePicker({
  required BuildContext context,
  required TimeOfDay initialTime,
}) {
  return showDialog<TimeOfDay>(
    context: context,
    builder: (BuildContext context) {
      return TimePickerDialog(
        initialTime: initialTime,
        initialEntryMode: TimePickerEntryMode.input,
      );
    },
  );
}