Dart - How to set the hour and minute of DateTime object

Question

How do I set/change the hour and/or minute of a DateTime object. Similar to Date.setHours(..) in JavaScript.

e.g If i did

var time = DateTime.parse("2018-08-16T11:00:00.000Z");

how do I set the hour and minute of time

Answer 1

now with extension u could do something like this

extension MyDateUtils on DateTime {
  DateTime copyWith({
    int? year,
    int? month,
    int? day,
    int? hour,
    int? minute,
    int? second,
    int? millisecond,
    int? microsecond,
  }) {
    return DateTime(
      year ?? this.year,
      month ?? this.month,
      day ?? this.day,
      hour ?? this.hour,
      minute ?? this.minute,
      second ?? this.second,
      millisecond ?? this.millisecond,
      microsecond ?? this.microsecond,
    );
  }
}

Answer 2

I got a simpler solution:

DateTime newDate = DateTime.now();
DateTime formatedDate = newDate.subtract(Duration(hours: newDate.hour, minutes: newDate.minute, seconds: newDate.second, milliseconds: newDate.millisecond, microseconds: newDate.microsecond));

Then the XX:XX from 'formatedDate' should be 00:00

Explanation:

formatedDate is a new DateTime variable with the content of newDate minus hours, minutes... from it

Answer 3

I believe this is a better solution than the accepted answer:

DateTime dateTime = DateFormat('dd-MM-yyyy h:mm:ssa', 'en_US').parseLoose('01-11-2020 2:00:00AM');

Answer 4

You can also do this by adding or subtracting to DateTime, using this package Jiffy. It also respects leap years and how many days are in each month

var updateTime = Jiffy("2018-08-16T11:00:00.000Z").add(hours: 1); // 2018-08-16 12:00:00.000Z

print(updateTime.dateTime); // 2018-08-16 12:30:00.000Z

// also you can format it
print(updateTime.format("yyyy, MMM")); // 2018, Aug

// or use default formats
print(updateTime.yMMMEdjm); // Thu, Aug 16, 2018 12:30 PM

Answer 5

I had some issues while using the formatted form of a DateTime object (using DateFormat) in my widget because showDatePicker brought a new instance of DateTime and calling setState doesn't have effect on the view.

There might be better ways to comply with my problem, but I decided to create my own one which is updateable using .update method.

import 'package:flutter/material.dart';

class MDateTime {
  int year, month, day, hour, min, sec;

  factory MDateTime.fromDateTime(DateTime dateTime) {
    return MDateTime(
      dateTime.year,
      dateTime.month,
      dateTime.day,
      dateTime.hour,
      dateTime.minute,
      dateTime.second,
    );
  }

  MDateTime([
    this.year = 0,
    this.month = 0,
    this.day = 0,
    this.hour = 0,
    this.min = 0,
    this.sec = 0,
  ]);

  void update({
    int? newYear,
    int? newMonth,
    int? newDay,
    int? newHour,
    int? newMin,
    int? newSec,
  }) {
    year = newYear ?? year;
    month = newMonth ?? month;
    day = newDay ?? day;
    hour = newHour ?? hour;
    min = newMin ?? min;
    sec = newSec ?? sec;
  }

  DateTime toDateTime() {
    return DateTime(year, month, day, hour, min, sec);
  }

  TimeOfDay toTimeOfDay() {
    return TimeOfDay(hour :hour, minute:  min);
  }

  String formatDate({String divider = "-"}){
    return "$year$divider$month$divider$day";
  }

  String formatTime({String divider = ":"}){
    return "$hour$divider$min$divider$sec";
  }
}

Moreover, there is no need to use another package for date-time formatting.

Answer 6

You can remove the current hours and minutes, and then add your wanted hours and minutes.

So if you would want to set the time to for example 23:59 you could do this:

    final date = DateTime.now();
    date
      ..subtract(Duration(hours: date.hour, minutes: date.minute))
      ..add(Duration(hours: 23, minutes: 59));

(Note that the other time units like seconds and milliseconds aren't changed here)

Answer 7

var newHour = 5; time = time.toLocal(); time = new DateTime(time.year, time.month, time.day, newHour, time.minute, time.second, time.millisecond, time.microsecond);