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moment-duration-format

Moment Duration Format

Format plugin for the Moment Duration object.

This is a plugin to the Moment.js JavaScript date library to add comprehensive formatting to Moment Durations.

Format template grammar is patterned on the existing Moment Date format template grammar, with a few modifications because durations are fundamentally different from dates.

This plugin does not have any dependencies beyond Moment.js itself, and may be used in the browser and in Node.js.


Formatting Numbers and Testing

Where it is available and functional, this plugin uses Number#toLocaleString to render formatted numerical output. Unfortunately, many environments do not fully implement the full suite of options in the toLocaleString spec, and some provide a buggy implementation.

This plugin runs a feature test for toLocaleString, and will revert to a fallback function to render formatted numerical output if the feature test fails. To force this plugin to always use the fallback number format function, set useToLocaleString to false. The fallback number format function output can be localized using options detailed at the bottom of this page. You should, in general, specify the fallback number formatting options if the default "en" locale formatting would be unacceptable on some devices or in some environments.

This plugin is tested using BrowserStack on a range of Android devices with OS versions from 2.2 to 7, and on a range of iOS devices with OS versions from 4.3 to 11. Also tested on Chrome, Firefox, IE 8-11, and Edge browsers.

Please raise an issue if you notice formatting issues or anomalies in any environment!


Roadmap

Version 2

A few items remain to finish off Version 2:

  • Add type definitions to support TypeScript, publish NuGet package, and support whatever other packaging options are in use these days.

  • Testing of the plugin should be modernized, ideally to match the Moment.js testing setup.

Version 3

Having implemented version 2 of the moment-duration-format plugin, there are some obvious improvements for a version 3.

The ideas below are logged as issues and tagged with the 3.0.0 milestone. If you have ideas or comments about what you'd like to see, please log an issue on this project!

  • The fallback number formatting localization options should be included with the Moment Locale object extensions this plugin already adds for localizing duration unit labels. This would put all of the localization configuration in one place.

  • moment-duration-format and its fallback number formatting function do not follow the same API as Number#toLocaleString for significant digits and faction digits. The fallback function should be updated to use the toLocaleString API, and the plugin should expose the toLocaleString API options directly rather than hiding some of the options and masking them behind precision and useSignificantDigits options.

  • Exposing the fallback number formatting function as well as the toLocaleString feature test function would facilitate testing and allow them to be used outside of the context of formatting durations.


Installation

The plugin depends on moment.js, which is not specified as a package dependency in the currently published version.

Node.js

npm install moment-duration-format

Bower

bower install moment-duration-format

Browser

<script src="path/to/moment-duration-format.js"></script>


Usage

This plugin will always try to install itself on the root.moment instance, if it exists.

This plugin will install its setup function to root.momentDurationFormatSetup so that it may be later called on any moment instance.

Browser

When using this plugin in the browser, if you do not include moment.js on your page first, you need to manually call window.momentDurationFormatSetup on your moment instance once it is created.

Module

To use this plugin as a module, use the require function.

var moment = require("moment");
var momentDurationFormatSetup = require("moment-duration-format");

The plugin exports the init function so that duration format can be initialized on other moment instances.

To use this plugin with any other moment.js package, for example moment-timezone, manually call the exported setup function to install the plugin into the desired package.

var moment = require("moment-timezone");
var momentDurationFormatSetup = require("moment-duration-format");
 
momentDurationFormatSetup(moment);
typeof moment.duration.fn.format === "function";
// true
typeof moment.duration.format === "function";
// true

Basics

Formatting a Single Duration

moment.duration.fn.format

The duration.fn.format method can format any moment duration. If no template or other arguments are provided, the default template function will generate a template string based on the duration's value.

moment.duration(123, "minutes").format();
// "2:03:00"
 
moment.duration(123, "months").format();
// "10 years, 3 months"

The duration format method may be called with three optional arguments, and returns a formatted string.

moment.duration(value, units).format([template] [, precision] [, settings])
// formattedString

Formatting Multiple Durations

moment.duration.format

The duration.format method allows coordinated formatting of multiple moment durations at once. This function accepts an array of durations as its first argument, then the same three optional arguments as the duration.fn.format function. This function returns an array of formatted strings.

moment.duration.format(durationsArray, [template] [, precision] [, settings]);
// formattedStringsArray

All of the options that are available to the single duration format function can be used with the multiple duration format function. A single settings object is used to format each of the individual durations.

moment.duration.format([
    moment.duration(1, "second"),
    moment.duration(1, "minute"),
    moment.duration(1, "hour")
], "d [days] hh:mm:ss");
// ["0:00:01", "0:01:00", "1:00:00"]
Invalid Durations

Invalid durations are treated as having a value of 0 for formatting.

var invalidDuration = moment.duration(NaN, "second");
 
invalidDuration.isValid();
// false
 
invalidDuration.format();
// "0 seconds"

Template

template (string|function) is the string used to create the formatted output, or a function that returns the string to be used as the format template.

Template String

moment.duration(123, "minutes").format("h:mm");
// "2:03"

The template string is parsed for moment token characters, which are replaced with the duration's value for each unit type. The moment tokens are:

years:   Y or y
months:  M
weeks:   W or w
days:    D or d
hours:   H or h
minutes: m
seconds: s
ms:      S

Escape token characters within the template string using square brackets.

moment.duration(123, "minutes").format("h [hrs], m [min]");
// "2 hrs, 3 mins"

Token Length

For some time duration formats, a zero-padded value is required. Use multiple token characters together to create the correct amount of padding.

moment.duration(3661, "seconds").format("h:mm:ss");
// "1:01:01"
 
moment.duration(15, "seconds").format("sss [s]");
// "015 s"

When the format template is trimmed, token length on the largest-magnitude rendered token can be trimmed as well. See sections trim and forceLength below for more details.

moment.duration(123, "seconds").format("h:mm:ss");
// "2:03"
Milliseconds Token Length

Token length of 2 for milliseconds is a special case, most likely used to render milliseconds as part of a timer output, such as mm:ss:SS. In this case, the milliseconds value is padded to three digits then truncated from the left to render a two digit output.

moment.duration(9, "milliseconds").format("mm:ss:SS", {
    trim: false
});
// "00:00:00"
 
moment.duration(10, "milliseconds").format("mm:ss:SS", {
    trim: false
});
// "00:00:01"
 
moment.duration(999, "milliseconds").format("mm:ss:SS", {
    trim: false
});
// "00:00:99"
 
moment.duration(1011, "milliseconds").format("mm:ss:SS", {
    trim: false
});
// "00:01:01"

Multiple Token Instances

Tokens can appear multiple times in the format template, but all instances must share the same length. If they do not, all instances will be rendered at the length of the first token of that type.

moment.duration(15, "seconds").format("ssss sss ss s");
// "0015 0015 0015 0015"
 
moment.duration(15, "seconds").format("s ss sss ssss");
// "15 15 15 15"

Default Template Function

The default template function attempts to format a duration based on its magnitude. The larger the duration value, the larger the units of the formatted output will be.

For some duration values, the default template function will default trim to "both" if that option is not set in the settings object (more on that below).

The default template function uses auto-localized unit labels (more on that below, also).

moment.duration(100, "milliseconds").format();
// "100 milliseconds"
 
moment.duration(100, "seconds").format();
// "1:40"
 
moment.duration(100, "days").format();
// "3 months, 9 days"
 
moment.duration(100, "weeks").format();
// "1 year, 10 months, 30 days"
 
moment.duration(100, "months").format();
// "8 years, 4 months"

Custom Template Function

Use a custom template function if you need runtime control over the template string. Template functions are executed with a this binding of the settings object, and have access to the underlying duration object via this.duration. Any of the settings may be accessed or modified by the template function.

This custom template function uses a different template based on the value of the duration:

function customTemplate() {
    return this.duration.asSeconds() >= 86400 ? "w [weeks], d [days]" : "hh:mm:ss";
}
 
moment.duration(65, 'seconds').format(customTemplate, {
    trim: false
});
// "00:01:05"
 
moment.duration(1347840, 'seconds').format(customTemplate, {
    trim: false
});
// "2 weeks, 2 days"

Punctuation Trimming

To ensure user-friendly formatted output, punctuation characters are trimmed from the beginning and end of the formatted output. Specifically, leading and trailing period ., comma ,, colon :, and space characters are removed.

Precision

precision (number) defines the number of decimal fraction or integer digits to display for the final value.

The default precision value is 0.

moment.duration(123, "minutes").format("h [hrs]");
// "2 hrs"

Positive precision defines the number of decimal fraction digits to display.

moment.duration(123, "minutes").format("h [hrs]", 2);
// "2.05 hrs"

Negative precision defines the number of integer digits to truncate to zero.

moment.duration(223, "minutes").format("m [min]", -2);
// "200 mins"

Settings

settings is an object that can override any of the default moment duration format options.

Both the template and precision arguments may be specified as properties of a single settings object argument, or they may be passed separately along with an optional settings object.

moment.duration(123, "minutes").format({
    template: "h [hrs]",
    precision: 2
});
// "2.05 hrs"

trim

The default trim behaviour is "large".

Largest-magnitude tokens are automatically trimmed when they have no value.

moment.duration(123, "minutes").format("d[d] h:mm:ss");
// "2:03:00"

Trimming also functions when the format string is oriented with token magnitude increasing from left to right.

moment.duration(123, "minutes").format("s [seconds], m [minutes], h [hours], d [days]");
// "0 seconds, 3 minutes, 2 hours"

To stop trimming altogether, set { trim: false }.

moment.duration(123, "minutes").format("d[d] h:mm:ss", {
    trim: false
});
// "0d 2:03:00"

When formatting multiple durations using moment.duration.format, trimming for all of the durations is coordinated on the union of the set of durations.

moment.duration.format([
    moment.duration(1, "minute"),
    moment.duration(1, "hour"),
    moment.duration(1, "day")
], "y [years], w [weeks], d [days], h [hours], m [minutes]");
// [
//    "0 days, 0 hours, 1 minute",
//    "0 days, 1 hour, 0 minutes",
//    "1 day, 0 hours, 0 minutes"
// ]

trim can be a string, a delimited list of strings, an array of strings, or a boolean. Accepted values are as follows:

  • ##### "large"

Trim largest-magnitude zero-value tokens until finding a token with a value, a token identified as stopTrim, or the final token of the format string. This is the default trim value.

moment.duration(123, "minutes").format("d[d] h:mm:ss");
// "2:03:00"
 
moment.duration(123, "minutes").format("d[d] h:mm:ss", {
    trim: "large"
});
// "2:03:00"
 
moment.duration(0, "minutes").format("d[d] h:mm:ss", {
    trim: "large"
});
// "0"
  • ##### "small"

Trim smallest-magnitude zero-value tokens until finding a token with a value, a token identified as stopTrim, or the final token of the format string.

moment.duration(123, "minutes").format("d[d] h:mm:ss", {
    trim: "small"
});
// "0d 2:03"
 
moment.duration(0, "minutes").format("d[d] h:mm:ss", {
    trim: "small"
});
// "0d"
  • ##### "both"

Execute "large" trim then "small" trim.

moment.duration(123, "minutes").format("d[d] h[h] m[m] s[s]", {
    trim: "both"
});
// "2h 3m"
 
moment.duration(0, "minutes").format("d[d] h[h] m[m] s[s]", {
    trim: "both"
});
// "0s"
  • ##### "mid"

Trim any zero-value tokens that are not the first or last tokens. Usually used in conjunction with "large" or "both". e.g. "large mid" or "both mid".

moment.duration(1441, "minutes").format("w[w] d[d] h[h] m[m] s[s]", {
    trim: "mid"
});
// "0w 1d 1m 0s"
 
moment.duration(1441, "minutes").format("w[w] d[d] h[h] m[m] s[s]", {
    trim: "large mid"
});
// "1d 1m 0s"
 
moment.duration(1441, "minutes").format("w[w] d[d] h[h] m[m] s[s]", {
    trim: "small mid"
});
// "0w 1d 1m"
 
moment.duration(1441, "minutes").format("w[w] d[d] h[h] m[m] s[s]", {
    trim: "both mid"
});
// "1d 1m"
 
moment.duration(0, "minutes").format("w[w] d[d] h[h] m[m] s[s]", {
    trim: "both mid"
});
// "0s"
  • ##### "final"

Trim the final token if it is zero-value. Use this option with "large" or "both" to output an empty string when formatting a zero-value duration. e.g. "large final" or "both final".

moment.duration(0, "minutes").format("d[d] h:mm:ss", {
    trim: "large final"
});
// ""
 
moment.duration(0, "minutes").format("d[d] h:mm:ss", {
    trim: "small final"
});
// ""
 
moment.duration(0, "minutes").format("d[d] h[h] m[m] s[s]", {
    trim: "both final"
});
// ""
  • ##### "all"

Trim all zero-value tokens. Shorthand for "both mid final".

moment.duration(0, "minutes").format("d[d] h[h] m[m] s[s]", {
    trim: "all"
});
// ""
  • ##### "left"

Maps to "large" to support this plugin's version 1 API.

  • ##### "right"

Maps to "large" to support this plugin's version 1 API.

  • ##### true

Maps to "large".

  • ##### null

Maps to "large".

  • ##### false

Disables trimming.

largest

Set largest to a positive integer to output only the n largest-magnitude moment tokens, starting with the largest-magnitude token that has a value.

Using the largest option defaults trim to "all".

moment.duration(7322, "seconds").format("d [days], h [hours], m [minutes], s [seconds]", {
    largest: 2
});
// "2 hours, 2 minutes"
 
moment.duration(1216800, "seconds").format("y [years], w [weeks], d [days], h [hours], m [minutes], s [seconds]", {
    largest: 3
});
// "2 weeks, 2 hours"

Setting trim to a different value, or using stopTrim can change the starting token as well as the remaining output.

moment.duration(1216800, "seconds").format("y [years], w [weeks], d [days], h [hours], m [minutes], s [seconds]", {
    largest: 3,
    trim: "both"
});
// "2 weeks, 0 days, 2 hours"
 
moment.duration(1216800, "seconds").format("y [years], w [weeks], d [days], h [hours], m [minutes], s [seconds]", {
    largest: 3,
    trim: "both",
    stopTrim: "m"
});
// "2 weeks, 0 days, 2 hours"
 
moment.duration(1216800, "seconds").format("y [years], w [weeks], d [days], h [hours], m [minutes], s [seconds]", {
    largest: 4,
    trim: false
});
// "2 weeks, 0 days, 2 hours, 0 minutes"
 
moment.duration(2, "hours").format("y [years], d [days], h [hours], m [minutes], s [seconds]", {
    trim: "both",
    stopTrim: "d m",
    largest: 2
});
// "0 days 2 hours"

stopTrim

Trimming will stop when a token listed in this option is reached.

Option value may be a moment token string, a delimited set of moment token strings, or an array of moment token strings. Alternatively, set stopTrim on tokens in the format template string directly using a * character before the moment token.

moment.duration(23, "minutes").format("d[d] h:mm:ss", {
    stopTrim: "h"
});
// "0:23:00"
 
moment.duration(23, "minutes").format("d[d] *h:mm:ss");
// "0:23:00"

This option affects all trimming modes: "large", "small", "mid", and "final".

moment.duration(2, "hours").format("y [years], d [days], h [hours], m [minutes], s [seconds]", {
    trim: "both",
    stopTrim: "d m"
});
// "0 days, 2 hours, 0 minutes"
 
moment.duration(2, "hours").format("y [years], *d [days], h [hours], *m [minutes], s [seconds]", {
    trim: "both"
});
// "0 days, 2 hours, 0 minutes"

trunc

Default behavior rounds the final token value.

moment.duration(179, "seconds").format("m [minutes]");
// "3 minutes"
 
moment.duration(3780, "seconds").format("h [hours]", 1);
// "1.1 hours"

Set trunc to true to truncate final token value. This was the default behavior in version 1 of this plugin.

moment.duration(179, "seconds").format("m [minutes]", {
    trunc: true
});
// "2 minutes"
 
moment.duration(3780, "seconds").format("h [hours]", 1, {
    trunc: true
});
// "1.0 hours"

Using trunc can affect the operation of trim and largest.

moment.duration(59, "seconds").format("d [days], h [hours], m [minutes]", {
    trunc: true,
    trim: "both"
});
// "0 minutes"
 
moment.duration(59, "seconds").format("d [days], h [hours], m [minutes]", {
    trunc: true,
    trim: "all"
});
// ""
 
moment.duration(59, "seconds").format("d [days], h [hours], m [minutes]", {
    trunc: true,
    largest: 1
});
// ""

minValue

Use minValue to render generalized output for small duration values, e.g. "< 5 minutes". minValue must be a positive number and is applied to the least-magnitude moment token in the format template.

moment.duration(59, "seconds").format("h [hours], m [minutes]", {
    minValue: 1
});
// "< 1 minute"

The minimum value will bubble up to larger-magnitude units if they are present in the format template.

moment.duration(59, "seconds").format("m:ss", {
    minValue: 60
});
// "< 1:00"

This option can be used in conjunction with trim, and is not affected by trunc.

moment.duration(59, "seconds").format("h [hours], m [minutes]", {
    minValue: 1,
    trim: "both"
});
// "< 1 minute"
 
moment.duration(59, "seconds").format("h [hours], m [minutes]", {
    minValue: 1,
    trunc: true,
    trim: "both"
});
// "< 1 minute"
 
moment.duration(59, "seconds").format("h [hours], m [minutes]", {
    minValue: 1,
    trim: false
});
// "< 0 hours, 1 minute"

minValue can be used with negative durations, where it has the same effect on the least-magnitude moment token's absolute value.

moment.duration(-59, "seconds").format("h [hours], m [minutes]", {
    minValue: 1
});
// "> -1 minute"

If minValue is a non-integer number, precision should be set as well so that the formatted output makes sense.

moment.duration(89, "seconds").format("m", {
    minValue: 1.5,
    precision: 1
});
// "< 1.5"
 
moment.duration(90, "seconds").format("m", {
    minValue: 1.5,
    precision: 1
});
// "1.5"

maxValue

Use maxValue to render generalized output for large duration values, e.g. "> 60 days". maxValue must be a positive number and is applied to the greatest-magnitude moment token in the format template. As with minValue, this option can be used in conjunction with trim, is not affected by trunc, and can be used with negative durations.

Using the maxValue option defaults trim to "all".

moment.duration(15, "days").format("w [weeks]", {
    maxValue: 2
});
// "> 2 weeks"
 
moment.duration(-15, "days").format("w [weeks]]", {
    maxValue: 2
});
// "< -2 weeks"

maxValue can be used with trim and largest, but when the maximum value is reached, all lesser-magnitude token values are forced to 0.

moment.duration(15.5, "days").format("w [weeks], d [days], h [hours]", {
    maxValue: 2,
    trim: false,
    largest: 2
});
// "> 2 weeks, 0 days"

If maxValue is a non-integer number, precision should be set as well so that the formatted output makes sense.

moment.duration(89, "seconds").format("m", {
    minValue: 1.5,
    precision: 1
});
// "< 1.5"
 
moment.duration(90, "seconds").format("m", {
    minValue: 1.5,
    precision: 1
});
// "1.5"

forceLength

Force the first moment token with a value to render at full length, even when the template is trimmed and the first moment token has a length of 1. Sounds more complicated than it is.

moment.duration(123, "seconds").format("h:mm:ss");
// "2:03"

If you want minutes to always be rendered with two digits, you can use a first token with a length greater than 1 (this stops the automatic token length trimming for the first token that has a value).

moment.duration(123, "seconds").format("hh:mm:ss");
// "02:03"

Or you can use { forceLength: true }.

moment.duration(123, "seconds").format("h:mm:ss", {
    forceLength: true
});
// "02:03"

useSignificantDigits

When useSignificantDigits is set to true, the precision option determines the maximum significant digits to be rendered. Precision must be a positive integer. Significant digits extend across unit types, e.g. "6 hours 37.5 minutes" represents 4 significant digits. Enabling this option causes token length to be ignored.

Using the useSignificantDigits option defaults trim to "all".

Setting trunc affects the operation of useSignificantDigits.

See the documentation for toLocaleString for more information on significant digits.

moment.duration(99999, "seconds").format("d [days], h [hours], m [minutes], s [seconds]", {
    useSignificantDigits: true,
    precision: 3
});
// "1 day, 3 hours, 50 minutes"
 
moment.duration(99999, "seconds").format("d [days], h [hours], m [minutes], s [seconds]", {
    useSignificantDigits: true,
    precision: 3,
    trunc: true
});
// "1 day, 3 hours, 40 minutes"
 
moment.duration(99999, "seconds").format("d [days], h [hours], m [minutes], s [seconds]", {
    useSignificantDigits: true,
    precision: 5
});
// "1 day, 3 hours, 46 minutes, 40 seconds"
 
moment.duration(99999, "seconds").format("d [days], h [hours], m [minutes], s [seconds]", {
    useSignificantDigits: true,
    trunc: true,
    precision: 5
});
// "1 day, 3 hours, 46 minutes, 30 seconds"
 
moment.duration(99999, "seconds").format("d [days], h [hours], m [minutes], s [seconds]", {
    useSignificantDigits: true,
    precision: 6
});
// "1 day, 3 hours, 46 minutes, 39 seconds"

useSignificantDigits can be used together with trim.

moment.duration(12.55, "hours").format("h:mm", {
    precision: 2,
    useSignificantDigits: true,
    trim: false
});
// "13:00"
 
moment.duration(12.55, "hours").format("h:mm", {
    precision: 2,
    useSignificantDigits: true,
    trim: false,
    trunc: true
});
// "12:00"

Localization

Formatted numerical output is rendered using toLocaleString if that built-in function is available and passes a feature test on plugin initialization. If the feature test fails, a fallback format function is used. See below for details on localizing output from the fallback format function.

Unit labels are automatically localized and pluralized. Unit labels are detected using the locale set in moment.js, which can be different from the locale of user's environment. This plugin uses custom extensions to the moment.js locale object, which can be easily added for any locale (see below).

It's likely that the options below do not address every i18n requirement for duration formatting (the plugin hasn't been tested on languages that are written from right to left, for instance), but they are a significant step in the right direction and support languages with multiple forms of plural).

userLocale

Numerical output is rendered using the locale set in moment.js, retrieved via moment.locale(). Set the userLocale option to render numerical output using a different locale.

moment.duration(1234567, "seconds").format("m [minutes]", 3);
// "20,576.117 minutes"
 
moment.duration(1234567, "seconds").format("m [minutes]", 3, {
    userLocale: "de-DE"
});
// "20.576,117 minutes"

Auto-Localized Unit Labels

The _ character can be used to generate auto-localized unit labels in the formatted output.

A single underscore _ will be replaced with the short duration unit label for its associated moment token.

A double underscore __ will be replaced with the standard duration unit label for its associated moment token.

moment.duration(2, "minutes").format("m _");
// "2 mins"
 
moment.duration(2, "minutes").format("m __");
// "2 minutes"

These are the default "en" locale options for unit labels. Unit label types and even the "_" character usage can be customized in the locale object extensions (see below).

Auto-Localized Time Notation

Durations can also be formatted with a localized time notation.

The string _HMS_ is replaced with a localized hour/minute/second time notation, e.g. h:mm:ss.

The string _HM_ is replaced with a localized hour/minute time notation, e.g. h:mm.

The string _MS_ is replaced with a localized minute/second time notation, e.g. m:ss.

moment.duration(3661, "seconds").format("_HMS_");
// "1:01:01"
 
moment.duration(3661, "seconds").format("_HM_");
// "1:01"
 
moment.duration(61, "seconds").format("_MS_");
// "1:01"

These are the default "en" locale options for duration time notation templates. Additional templates may be created in the locale object extensions (see below).

usePlural

Unit label pluralization is automatically corrected when unit labels appear in the text associated with each moment token. The default "en" locale extension includes long and short unit labels, and a basic pluralization function. Unit labels, unit label types, and the pluralization function can be customized for a locale (see below).

moment.duration(1, "minutes").format("m [minutes]");
// "1 minute"
 
moment.duration(1, "minutes").format("m [mins]");
// "1 min"
 
moment.duration(2, "minutes").format("m [minute]");
// "2 minutes"
 
moment.duration(2, "minutes").format("m [min]");
// "2 mins"

Set usePlural to false to disable auto-correction of pluralization.

moment.duration(1, "minutes").format("m [minutes]", {
    usePlural: false
});
// "1 minutes"
 
moment.duration(1, "minutes").format("m [mins]", {
    usePlural: false
});
// "1 mins"
 
moment.duration(2, "minutes").format("m [minute]", {
    usePlural: false
});
// "2 minute"
 
moment.duration(2, "minutes").format("m [min]", {
    usePlural: false
});
// "2 min"

The default pluralization function for the "en" locale outputs a plural unit name when a value is rendered with decimal precision.

moment.duration(1, "minutes").format("m [minutes]", 2);
// "1.00 minutes"

useLeftUnits

The text to the right of each moment token in a template string is treated as that token's units for the purposes of trimming, pluralizing, and localizing. To properly process a template string where the token/unit association is reversed, set useLeftUnits to true.

moment.duration(7322, "seconds").format("_ h, _ m, _ s", {
    useLeftUnits: true
});
// "hrs 2, mins 2, secs 2"

useGrouping

Formatted numerical output is rendered using toLocaleString with the option useGrouping enabled. Set useGrouping to false to disable digit grouping.

moment.duration(1234, "seconds").format("s [seconds]");
// "1,234 seconds"
 
moment.duration(1234, "seconds").format("s [seconds]", {
    useGrouping: false
});
// "1234 seconds"

Extending Moment's locale object

This plugin now extends the moment.js locale object with duration labels, duration label types, duration time-notation templates, and a pluralization function. The "en" locale is included with this plugin. Other locales may be defined using the moment.js locale API to provide auto-pluralized and auto-localized unit labels in different languages. If the plugin cannot find the duration locale extensions for the active moment locale, the plugin will fall back to the "en" locale.

Below is the default "en" locale extension.

moment.updateLocale('en', {
    durationLabelsStandard: {
        S: 'millisecond',
        SS: 'milliseconds',
        s: 'second',
        ss: 'seconds',
        m: 'minute',
        mm: 'minutes',
        h: 'hour',
        hh: 'hours',
        d: 'day',
        dd: 'days',
        w: 'week',
        ww: 'weeks',
        M: 'month',
        MM: 'months',
        y: 'year',
        yy: 'years'
    },
    durationLabelsShort: {
        S: 'msec',
        SS: 'msecs',
        s: 'sec',
        ss: 'secs',
        m: 'min',
        mm: 'mins',
        h: 'hr',
        hh: 'hrs',
        d: 'dy',
        dd: 'dys',
        w: 'wk',
        ww: 'wks',
        M: 'mo',
        MM: 'mos',
        y: 'yr',
        yy: 'yrs'
    },
    durationTimeTemplates: {
        HMS: 'h:mm:ss',
        HM: 'h:mm',
        MS: 'm:ss'
    },
    durationLabelTypes: [
        { type: "standard", string: "__" },
        { type: "short", string: "_" }
    ],
    durationPluralKey: function (token, integerValue, decimalValue) {
        // Singular for a value of `1`, but not for `1.0`.
        if (integerValue === 1 && decimalValue === null) {
            return token;
        }
 
        return token + token;
    }
});
Creating a new Moment locale extension

The duration extensions for a new locale might look something like the following example, which includes an additional unit label type, a custom time-notation template, and an additional form of plural.

This example provides new values for all of the duration locale extensions. In a new locale, you can include updates for one or more of the duration locale extensions, and any that you do not include will automatically fall back to the "en" versions in this plugin. e.g. your locale could update only the durationLabelsShort object, or only the durationPluralKey function, if those were the only differences from the default "en" locale configuration.

New types of duration labels must have a key that begins with durationLabels and must be enumerated in durationLabelTypes.

This locale uses a single token "s" for the singular label, a double token "ss" for the plural label when the value is 2, and a triple token "sss" for the plural label for values greater than 3. For brevity, only labels for the seconds type are included.

Unit labels are replaced after the format template string is tokenized, so they need not be escaped. Time-notation templates are replaced before the format template string is tokenized, so they must be escaped.

moment.updateLocale('sample', {
    durationLabelsLong: {
        s: 'singular long second',
        ss: 'first long plural seconds',
        sss: 'next long plural seconds'
        // ...
    },
    durationLabelsStandard: {
        s: 'singular second',
        ss: 'first plural seconds',
        sss: 'next plural seconds'
        // ...
    },
    durationLabelsShort: {
        s: 'singular sec',
        ss: 'first plural secs',
        sss: 'next plural secs'
        // ...
    },
    durationTimeTemplates: {
        HS: 'hh[h].ssss[s]'
        // ...
    },
    durationLabelTypes: [
        { type: "long", string: "___" },
        { type: "standard", string: "__" },
        { type: "short", string: "_" }
    ],
    durationPluralKey: function (token, integerValue, decimalValue) {
        // Decimal value does not affect unit label for this locale.
 
        // "xxx" for > 2.
        if (integerValue > 2) {
            return token + token + token;
        }
 
        // "x" for === 1.
        if (integerValue === 1) {
            return token;
        }
 
        // "xx" for others.
        return token + token;
    }
});
durationPluralKey

The function for durationPluralKey is passed three arguments:

  • token

String. A single character representing the unit type.

years:   y
months:  M
weeks:   w
days:    d
hours:   h
minutes: m
seconds: s
ms:      S
  • integerValue

Number. The integer portion of the token's value.

  • decimalValue

Number. The decimal fraction portion of the token's value.

Localization and the Fallback Number Format Function

You can (and likely should) set the localization options for the fallback number format function if the default "en" locale formatting is not acceptable on some devices or in some environments.

useToLocaleString

Set this option to false to ignore the toLocaleString feature test and force the use of the formatNumber fallback function included in this plugin.

The fallback number format options will have no effect when toLocaleString is used. The grouping separator, decimal separator, and integer digit grouping will be determined by the user locale.

moment.duration(100000.1, "seconds").format("s", {
    userLocale: "de-DE",
    precision: 2,
    decimalSeparator: ",",
    groupingSeparator: "."
});
// "100.000,10" on all devices and in all environemnts.

groupingSeparator

The integer digit grouping separator used when using the fallback number format function. Default value is a , character.

decimalSeparator

The decimal separator used when using the fallback number format function. Default value is a . character.

grouping

The integer digit grouping used when using the fallback number format function. Must be an array. The default value of [3] gives the standard 3-digit thousand/million/billion digit groupings for the "en" locale. Setting this option to [3, 2] would generate the thousand/lakh/crore digit groupings used in the "en-IN" locale.

// Force the use of the fallback number format function. Do not use toLocaleString.
// We're in some sort of strange hybrid french-indian locale...
moment.duration(100000000000, "seconds").format("m", {
    useToLocaleString: false,
    precision: 2,
    decimalSeparator: ",",
    groupingSeparator: " ",
    grouping: [3, 2]
});
// "1 66 66 66 666,67");