Guys. I want to write a simple code to add X weeks to a chosen Date but I just can't figure out how. I always get a ton of errors. The function should basically return the chosen date plus "addedweeks" in the format "dd-MM-yyyy". Below is my last attempt. Thanks in advance!
import 'dart:math' as math;
String? addXWeeks(
DateTime? datum,
int? addedweeks,
) {
// add 2 weeks
DateTime date = datum.toLocal;
date = DateTime(date.year, date.month, date.day + (addedweeks*7));
}
this is very easy. DateTime has a method called add. You only need to add 7 days, because duration has not the propertie "weeks".
Here is a samle:
void main() {
// Current date
DateTime date = DateTime.now();
// Weeks you want to add
int weeksToAdd = 10;
print("Before: $date");
// Multiply 7 (days a week) with your week and set int to and int
date = date.add(Duration(days: (7 * weeksToAdd).toInt()));
print("After: $date");
// Format date
print("Format date: ${date.day}.${date.month}.${date.year}");
}
The output:
Before: 2022-10-06 13:23:16.342888
After: 2022-12-15 12:23:16.342888
Format date: 15.12.2022
Related
I have a scenario where user selects a start date and end date and user also selects a specific day I need to show that specific day with date that occurs between them.
I tried the Intl package difference method but did not work
You can use this method. Takes the start and end date and also the weekday. Note, can pass in 3 as an int or 'DateTime.wednesday' as the argument.
Note, idea based on mirkancal's answer in this thread
List<DateTime> getAllDatesOfAWeekday(
{required DateTime startDate,
required DateTime endDate,
required int weekday}) {
List<DateTime> allDates = [];
for (int i = 0; i <= endDate.difference(startDate).inDays; i++) {
if (startDate.add(Duration(days: i)).weekday == weekday) {
allDates.add(startDate.add(Duration(days: i)));
}
}
return allDates;
}
I'm new to Flutter and I'm trying to output the start of the current day in UTC format.
I use Flutter 3.3.7 and Dart SDK 2.18.4.
First, I take the current date.
DateTime dt = DateTime.now();
Next, I use extension for the DateTime class, which I implemented myself.
extension DateTimeFromTimeOfDay on DateTime {
DateTime appliedFromTimeOfDay(TimeOfDay timeOfDay) {
return DateTime(year, month, day, timeOfDay.hour, timeOfDay.minute);
}
}
It outputs the same date, only with the time that I pass it via TimeOfDay class(In this case 00:00).
dt = dt.appliedFromTimeOfDay(const TimeOfDay(hour: 0, minute: 0));
print(dt.toUtc()); //2022-11-08 21:00:00.000Z
But when I run this code, it outputs a date with a non-zero time.
I also tried adding the toUtc() method to the extension.
extension DateTimeFromTimeOfDay on DateTime {
DateTime appliedFromTimeOfDay(TimeOfDay timeOfDay) {
return DateTime(year, month, day, timeOfDay.hour, timeOfDay.minute).toUtc();
}
}
That didn't work either.
How can I get the DateTime in UTC format with zeroed time of day? For example,
2022-11-08 00:00:00.000Z
DateTime has a utc constructor that allows you to do this.
extension DateTimeFromTimeOfDay on DateTime {
DateTime appliedFromTimeOfDay(TimeOfDay timeOfDay) {
return DateTime.utc(year, month, day, timeOfDay.hour, timeOfDay.minute);
}
}
DateTime today = DateTime.now()
.appliedFromTimeOfDay(const TimeOfDay(hour: 0, minute: 0)); // output: 2022-11-09 00:00:00.000Z (note the Z which indicate UTC)
Try it with this extension method
extension DateTimeExtension on DateTime {
DateTime getDateOnly() {
return DateTime(this.year, this.month, this.day);
}
}
This question already has answers here:
How do I convert a date/time string to a DateTime object in Dart?
(8 answers)
unable to convert string date in Format yyyyMMddHHmmss to DateTime dart
(11 answers)
Closed last year.
Hi i have an array contains
List<dynamic> am = ['09:00', '09:30', '10:00', '10:30', '11:00', '11:30'];
and if they are selected
String time = '09:00'
how can I change time to the DateTime value or TimeOfDay
import 'package:intl/intl.dart';
if your time format is fixed (for example "hours:minutes" ) you can use this method
DateTime? _convertStringToDateTime(String time){
DateTime? _dateTime;
try{
_dateTime = DateFormat("hh:mm").parse(time);
}catch(e){}
return _dateTime;
}
You can use this:
TimeOfDay toTimeOfDay(String time){
List<String> timeSplit = time.split(":");
int hour = int.parse(timeSplit.first);
int minute = int.parse(timeSplit.last);
return TimeOfDay(hour: hour, minute: minute);
}
https://pub.dev/packages/date_format
See this package, By means of this package you can format your DateTime.
I have 2 times which I need to do subtract and I am almost close but there is one big issue
I have 2 times in string-like 10:00AM and 10:00PM
And my code is this
var df = DateFormat("hh:mm");
var durationStart = DateFormat('HH:mm').format(df.parse(10:00AM));
var durationEnd = DateFormat('HH:mm').format(df.parse(10:00PM));
print('durationStart ${durationStart}');
print('durationEnd ${durationEnd}');
var Startparts = durationStart.split(':');
var startDurationSet = Duration(hours: int.parse(Startparts[0].trim()), minutes: int.parse(Startparts[1].trim()));
var Endparts = durationEnd.split(':');
var endDurationSet = Duration(hours: int.parse(Endparts[0].trim()), minutes: int.parse(Endparts[1].trim()));
print('startDurationSet ${startDurationSet}');
var result = Duration(hours: int.parse(Endparts[0].trim()) - int.parse(Startparts[0].trim()) , minutes: int.parse(Startparts[1].trim()) - int.parse(Endparts[1].trim()));
print('result ${result.toString().replaceAll('-', '')}');
So I have 2 times one is startTime and one is End time. I simply need a difference between hours. for example, I have 10:00Am and 01:00PM i need 3hours but it's showing 9hours. But what I am receiving is if I have 10:00AM and 10:00pm it's showing 0 hours but its needs to show 12. Same
It is easy if you can get your start and end date in DateTime properly
Hint, I use "hh:mma" since that is your original format => "10:00AM"
If I use "HH:mm" like you do, i'll always get the same time since it doesn't parse the AM/PM after the 10:00
// Get your time in term of date time
DateTime startDate = DateFormat("hh:mma").parse("10:00AM");
DateTime endDate = DateFormat("hh:mma").parse("10:00PM");
// Get the Duration using the diferrence method
Duration dif = endDate.difference(startDate);
// Print the result in any format you want
print(dif.toString(); // 12:00:00.000000
print(dif.inHours); // 12
Are you looking for something like this?
TimeOfDay _calcTimeOfDay(int hour, int minute) {
if (minute > 60) {
minute = (minute % 60);
hour += 1;
}
return TimeOfDay(hour: hour, minute: minute);
}
The problem is if you have hour=24 and minute=75 then the hour would be 25, which is not a valid hour.
Not sure I fully understand the question, maybe if you can provide more info.
What you need to add on your DateFormat is the code for am/pm marker: a. Using either format hh:mma or h:ma should work.
You can then use DateTime.difference() to calculate the time variance from durationStart and durationEnd. Here's a sample that you can run on DartPad.
import 'package:intl/intl.dart';
void main() {
/// Set the format that of the Date/Time that like to parse
/// h - 12h in am/pm
/// m - minute in hour
/// a - am/pm marker
/// See more format here: https://pub.dev/documentation/intl/latest/intl/DateFormat-class.html
var dateFormat = DateFormat('h:ma');
DateTime durationStart = dateFormat.parse('10:00AM');
DateTime durationEnd = dateFormat.parse('10:00PM');
print('durationStart: $durationStart');
print('durationEnd: $durationEnd');
/// Fetch the difference using DateTime.difference()
/// https://api.flutter.dev/flutter/dart-core/DateTime/difference.html
print('difference: ${durationEnd.difference(durationStart).inHours}');
}
Use package
intl: ^0.17.0
import 'package:intl/intl.dart';
var dateFormat = DateFormat('h:ma');
DateTime durationStart = dateFormat.parse('10:00AM');
DateTime durationEnd = dateFormat.parse('1:00PM');
print('durationStart: $durationStart');
print('durationEnd: $durationEnd');
var differenceInHours = durationEnd.difference(durationStart).inHours;
print('difference: $differenceInHours hours');
I have created one class for you:
import 'package:intl/intl.dart';
class DateUtils {
static String getTimeDifference(String startTime, String endTime){
/// Set the format that of the Date/Time that like to parse
/// h - 12h in am/pm
/// m - minute in hour
/// a - am/pm marker
/// See more format here: https://pub.dev/documentation/intl/latest/intl/DateFormat-class.html
var dateFormat = DateFormat('h:ma');
DateTime durationStart = dateFormat.parse(startTime);
DateTime durationEnd = dateFormat.parse(endTime);
return '${durationEnd.difference(durationStart).inHours} hours';
}
}
How you can use:
void main() {
print("10:00PM, 10:30PM => " + DateUtils.getTimeDifference("10:00PM", "10:30PM"));
print("12:00AM, 04:00AM => " + DateUtils.getTimeDifference("12:00AM", "04:00AM"));
print("01:00AM, 03:00AM => " + DateUtils.getTimeDifference("01:00AM", "03:00AM"));
print("12:00AM, 06:00PM => " + DateUtils.getTimeDifference("12:00AM", "06:00PM"));
print("04:00PM, 03:00PM => " + DateUtils.getTimeDifference("04:00PM", "03:00PM"));
}
Output:
10:00PM, 10:30PM => 0 hours
12:00AM, 04:00AM => 4 hours
01:00AM, 03:00AM => 2 hours
12:00AM, 06:00PM => 18 hours
04:00PM, 03:00PM => -1 hours
Hope it will be helpful.
The Calendar clicked signal returns a date as follows:
2015-11-13T00:00:00
However, I would like to have a date formatted like this:
Fri Nov 13 2015
This is what I tried:
onSelectedDateChanged:
{
calender.visible = false;
selectedDate = selectedDate.toLocaleTimeString(Qt.LocalDate, Locale.ShortFormat);
textOfSelectedDate.text = Date.fromLocaleTimeString(Qt.LocalDate, selectedDate, Locale.ShortFormat)}
}
textOfSelectedDate is the id of the text box where this date will be displayed.
How can I extract day, month, and year in a desired format from Date returned by Calender?
QML's date type extends Javascript's Date. Thus you can do:
onSelectedDateChanged: {
const day = selectedDate.getDate();
const month = selectedDate.getMonth() + 1; //assuming you want 1..12, getMonth()'s return value is zero-based!
const year = selectedDate.getFullYear();
...
}
First of all, date is similar to JS date type. So you can use all its functions, like getDate() etc. See it here
Also, you can use Qt.formatDate() object to format the result. In your case it can be as follows:
onClicked: {
console.log(Qt.formatDate(date,"ddd MMM d yyyy"))
}