Countdown timer in flutter - flutter

Question

I want to make a flutter countdown timer to display remaining registration time (DD-HH-MM).
Example:
What would be the most efficient way of accomplishing this?
Thank you

Answer 1

Change below code as your design and requirement
DateTime startTime = DateTime(2020,03,04);
Duration remaining = DateTime.now().difference(DateTime.now());
Timer t;
int days=0,hrs =0, mins=0;
#override
void initState(){
super.initState();
startTimer();
}
startTimer()async{
t = Timer.periodic(Duration(seconds:1),(timer){
setState((){
remaining = DateTime.now().difference(startTime);
mins = remaining.inMinutes;
hrs = mins>=60 ? mins~/60:0;
days = hrs>=24 ? hrs~/24: 0;
hrs = hrs%24;
mins = mins%60;
});
});
}
#override
Widget build(BuildContext context) {
return Scaffold(
backgroundColor: Colors.white,
body: Center(
child: Column(
mainAxisSize: MainAxisSize.min,
children: <Widget>[
Padding(
padding: const EdgeInsets.all(8.0),
child: Text('Registration closes in',
style: TextStyle(color: Colors.black, fontSize: 20),
textAlign: TextAlign.center),
),
Row(
mainAxisAlignment:MainAxisAlignment.spaceEvenly,
children: [
Expanded(
child: Padding(
padding: const EdgeInsets.all(8.0),
child: Text('$days',
style: TextStyle(color: Colors.black, fontSize: 20),
textAlign:TextAlign.center,),
),
),
Expanded(
child: Padding(
padding: const EdgeInsets.all(8.0),
child: Text('$hrs',
style: TextStyle(color: Colors.black, fontSize: 20),
textAlign:TextAlign.center,),
),
),
Expanded(
child: Padding(
padding: const EdgeInsets.all(8.0),
child: Text('$mins',
style: TextStyle(color: Colors.black, fontSize: 20),
textAlign:TextAlign.center,),
),
),
]),
Row(
mainAxisAlignment:MainAxisAlignment.spaceEvenly,
children: [
Expanded(
child: Padding(
padding: const EdgeInsets.all(8.0),
child: Text('Days',
style: TextStyle(color: Colors.black, fontSize: 16),
textAlign:TextAlign.center,),
),
),
Expanded(
child: Padding(
padding: const EdgeInsets.all(8.0),
child: Text('Hours',
style: TextStyle(color: Colors.black, fontSize: 16),
textAlign:TextAlign.center,),
),
),
Expanded(
child: Padding(
padding: const EdgeInsets.all(8.0),
child: Text('Minutes',
style: TextStyle(color: Colors.black, fontSize: 16),
textAlign:TextAlign.center,),
),
),
]),
],
)));
}