How to Add or Subtract Days from DateTime in Dart/Flutter

In this example, we are going to show you the easiest way to add or subtract duration from DateTime in Dart and Flutter. You will learn to add or subtract durations on days, seconds, minutes, hours, and more. See the example below:

DateTime.add(Duration):

DateTime dt1 = DateTime.parse("2021-12-23 11:47:00");

DateTime dt2 = dt1.add(Duration(seconds: 10));
print(dt2);
//Output: 2021-12-23 11:47:10.000

DateTime dt3 = dt1.add(Duration(minutes: 10, seconds: 30));
print(dt3);
//Output: 2021-12-23 11:57:30.000

DateTime dt4 = dt1.add(Duration(hours: 20));
print(dt4);
//Output: 2021-12-24 07:47:00.000

DateTime dt5 = dt1.add(Duration(days: 20));
print(dt5);
//Output: 2022-01-12 11:47:00.000

DateTime.subtract(Duration):

DateTime dt1 = DateTime.parse("2021-12-23 11:47:00");

DateTime dt2 = dt1.subtract(Duration(seconds: 10));
print(dt2);
//Output: 2021-12-23 11:46:50.000

DateTime dt3 = dt1.subtract(Duration(minutes: 10, seconds: 30));
print(dt3);
//Output: 2021-12-23 11:36:30.000

DateTime dt4 = dt1.subtract(Duration(hours: 20));
print(dt4);
//Output: 2021-12-22 15:47:00.000

DateTime dt5 = dt1.subtract(Duration(days: 20));
print(dt5);
//Output: 2021-12-03 11:47:00.000

Flutter/Dart Example:

import 'package:flutter/material.dart';

void main() {
  runApp( MaterialApp(
       home: Home()
  ));
}

class Home extends  StatefulWidget {
  @override
  State<Home> createState() => _HomeState();
}

class _HomeState extends State<Home> {

  @override
  Widget build(BuildContext context) {

    DateTime dt1 = DateTime.parse("2021-12-23 11:47:00");

    return Scaffold(
         appBar: AppBar(
            title: Text("Add/Subtract Duration from DateTime"),
            backgroundColor: Colors.redAccent,
         ),
          body: Container(
             alignment: Alignment.center,
             padding: EdgeInsets.all(20),
             child: Column(
               children:[
         
                      Text("Date and Time:" + dt1.toString()),

                      Text("2 days added: " + dt1.add(Duration(days: 2)).toString()),
                      Text("5 days 4 Hours Added: " + dt1.add(Duration(days: 5, hours: 4)).toString()),

                      Text("10 days 20 Hours Subtracted: " + dt1.subtract(Duration(days: 10, hours: 20)).toString()),

                ]
             ),
          )
      );
  }
}

Output Screenshot:

In this way, you can add or subtract duration from Date and Time in Dart/Flutter.