A Moment.js inspired package.


Import the package

import "package:moment_dart/moment_dart.dart";

Create Moment instance

final Moment now = Moment.now();

final Moment epoch = Moment(DateTime.fromMicrosecondsSinceEpoch(0, isUtc: true));

final Moment derived = DateTime(2003,06,01).toMoment();

Use it!

final Moment moment = Moment.now() - Duration(days: 1); // May 14, 2022

moment.calendar(); // Yesterday

moment.fromNow(); // a day ago

// You can omit the prefix/suffix
moment.from(moment - Duration(days: 365), true); // a year

/// Unmatched strings will be left as is.
moment.format("YYYY년 MMMM Do dddd hh:mma"); // 2022년 May 14 Saturday 08:09pm

Change localization

When localization is omitted, it defaults to English (United States)

final Moment hangulday = Moment(DateTime(2022,10,9), localization: MomentLocalizations.ko());

hangulday.format("ll"); // 2022년 10월 9

You can also take advantage of localization, as it's kinda the main character

final MomentLocalization localization = MomentLocalizations.enUS();

localization.relative(const Duration(seconds: 2)); //in a few seconds
localization.weekdayName(yesterday.weekday); // "Monday"

Even if you don't use moment, you can use MomentBenefits extension by importing the package :)

final DateTime date = DateTime(2022,03,29);

//Returns the ISO Week number of the year
// [1,2,3,...,52,53]
date.week == 13; // true

// Returns the year according to ISO Week
date.weekYear == 2022; // true

// Returns the quarter of the year. [][Jan,Feb,Mar][Apr,May,Jun][Jul,Aug,Sep][Oct,Nov,Dec]
// [1,2,3,4]
date.quarter == 1; // true

// Returns if the [year] is leap year
date.isLeapYear == false; // true

/// Returns ordinal day of the year
/// [1,2,3,...,365,366]
date.dayOfYear == 88; // true

Read more about ISO week on Wikipedia

Creating your own Localzation

First, extend the Localization abstract class.

Almost everything is declared as function, so you can freely achieve the unique features of your language.

  CatLanguage extends MomentLocalization {
    String relative(Duration duration, [bool dropPrefixOrSuffix = false]) => "a two meow ago";

    String weekdayName(int i) => "Meowday #$i";

    String calendar(Moment moment, {Moment? reference, bool weekStartOnSunday = false, bool omitHours = false}) => "Last Meowday";

    /// Please refer to the [FormatterToken] enum for details.
    /// It contains almost all of the tokens mentioned in https://momentjs.com/docs/#/parsing/string-format/
    Map<FormatterToken, FormatterTokenFn?> formats() => {};

    String languageCodeISO() => "meow";

    String endonym() => "Meow-meow meow";

    String locale() => "meow";

    String languageNameInEnglish() => "Cat tongue";

Available Localization classes:

Localizations are classes that extend MomentLocalization

  • LocalizationEnUs (English - United States) en_US
  • LocalizationKorean (Korean) ko
  • LocalizationGermanStandard (German) de_DE
  • LocalizationMongolianCyrillic (Mongolian) mn
    • LocalizationMongolianTraditional (Mongolian) mn
    • LocalizationMongolianTraditionalNumbers (Uses traditional Mongolian numbers)


  • Add more localizations
  • Implement parsing string produced from Moment.format($)


Support for doing something awesome. [...]