/javascript-time-ago

International highly customizable relative time formatting

Primary LanguageJavaScriptMIT LicenseMIT

javascript-time-ago

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International higly customizable relative date/time formatter (both for past and future dates).

Formats a date to something like:

  • just now
  • 5m
  • 15 min
  • 25 minutes
  • half an hour ago
  • an hour ago
  • 2h
  • yesterday
  • 2d
  • 1wk
  • 2 weeks ago
  • 3 weeks
  • half a month ago
  • 1 mo. ago
  • 2 months
  • half a year
  • a year
  • 2yr
  • 5 years ago
  • … or whatever else

Installation

npm install intl-messageformat@^1.3.0 --save
npm install javascript-time-ago --save

This package assumes that the Intl global object exists in the runtime. Intl is present in all modern browsers except Internet Explorer 10 and Safari 9 (which can be solved with the Intl polyfill).

Node.js starting from 0.12 has the Intl APIs built-in, but only includes the English locale data by default. If your app needs to support more locales than English, you'll need to get Node to load the extra locale data, or (a much simpler approach) just install the Intl polyfill.

If you decide you need the Intl polyfill then here are some basic installation and configuration instructions

Usage

import javascriptTimeAgo from 'javascript-time-ago'

// Load locale specific relative date/time messages
//
javascriptTimeAgo.locale(require('javascript-time-ago/locales/en'))
javascriptTimeAgo.locale(require('javascript-time-ago/locales/ru'))

// Load number pluralization functions for the locales.
// (the ones that decide if a number is gonna be 
//  "zero", "one", "two", "few", "many" or "other")
// http://cldr.unicode.org/index/cldr-spec/plural-rules
// https://github.com/eemeli/make-plural.js
// http://www.unicode.org/cldr/charts/latest/supplemental/language_plural_rules.html
//
require('javascript-time-ago/intl-messageformat-global')
require('intl-messageformat/dist/locale-data/en')
require('intl-messageformat/dist/locale-data/ru')

// Initialization complete.
// Ready to format relative dates and times.

const timeAgoEnglish = new javascriptTimeAgo('en-US')

timeAgoEnglish.format(new Date())
// "just now"

timeAgoEnglish.format(new Date(Date.now() - 60 * 1000))
// "a minute ago"

timeAgoEnglish.format(new Date(Date.now() - 2 * 60 * 60 * 1000))
// "2 hours ago"

timeAgoEnglish.format(new Date(Date.now() - 24 * 60 * 60 * 1000))
// "a day ago"

const timeAgoRussian = new javascriptTimeAgo('ru-RU')

timeAgoRussian.format(new Date())
// "только что"

timeAgoRussian.format(new Date(Date.now() - 60 * 1000)))
// "минуту назад"

timeAgoRussian.format(new Date(Date.now() - 2 * 60 * 60 * 1000)))
// "2 часа назад"

timeAgoRussian.format(new Date(Date.now() - 24 * 60 * 60 * 1000))
// "днём ранее"

Twitter style

Mimics Twitter style time ago ("1m", "2h", "Mar 3", "Apr 4, 2012")

…
const timeAgo = new javascriptTimeAgo('en-US')

// A `style` is simply an `options` object 
// passed to the `.format()` function as a second parameter.
const twitter = timeAgo.style.twitter()

timeAgo.format(new Date(), twitter)
// ""

timeAgo.format(new Date(Date.now() - 60 * 1000), twitter)
// "1m"

timeAgo.format(new Date(Date.now() - 2 * 60 * 60 * 1000), twitter)
// "2h"

Fuzzy style

timeAgo.style.fuzzy()

The time scale is (actually the same as the default style but with "ago" omitted):

  • just now
  • 1 minute
  • 2 minutes
  • 5 minutes
  • 10 minutes
  • 15 minutes
  • 20 minutes
  • half an hour
  • an hour
  • 2 hours
  • …
  • 20 hours
  • 1 day
  • 2 days
  • 3 days
  • 4 days
  • 5 days
  • a week
  • 2 weeks
  • 3 weeks
  • a month
  • 2 months
  • 3 months
  • 4 months
  • half a year
  • a year
  • 2 years
  • 3 years
  • …

Intl polyfill installation

To install the Intl polyfill (supporting 200+ languages):

npm install intl --save

Then configure the Intl polyfill:

Localization

This library currently comes with English and Russian localization built-in, but any other locale can be added easily at runtime (Pull Requests adding new locales are accepted too).

The built-in localization resides in the locales folder.

The format of the localization is:

{
  …
  "day": 
  {
    "previous": "a day ago",
    "now": "today",
    "next": "in a day",
    "past":
    {
      "one": "{0} day ago",
      "other": "{0} days ago"
    },
    "future":
    {
      "one": "in {0} day",
      "other": "in {0} days"
    }
  },
  …
}

The past and future keys can be one of: zero, one, two, few, many and other. For more info on which is which read the official Unicode CLDR documentation. Unicode CLDR (Common Locale Data Repository) is an industry standard and is basically a collection of formatting rules for all locales (date, time, currency, measurement units, numbers, etc).

One can also use raw Unicode CLDR locale rules which will be automatically converted to the format described above.

Example for en-US-POSIX locale

{
  "main": {
    "en-US-POSIX": {
      "dates": {
        "fields": {
          …
          "day": {
            "displayName": "day",            // ignored
            "relative-type--1": "yesterday", // ignored
            "relative-type-0": "today",      // ignored
            "relative-type-1": "tomorrow",   // ignored
            "relativeTime-type-future": {
              "relativeTimePattern-count-one"   : "in {0} day",
              "relativeTimePattern-count-other" : "in {0} days"
            },
            "relativeTime-type-past": {
              "relativeTimePattern-count-one"   : "{0} day ago",
              "relativeTimePattern-count-other" : "{0} days ago"
            }
          },
          …
        }
      }
    }
  }
}

To add support for a specific language one can download the CLDR dates package:

npm install cldr-dates-modern --save

And then add the neccessary locales from it:

import javascriptTimeAgo from 'javascript-time-ago'
import russian from 'cldr-dates-modern/main/ru/dateFields.json'

javascriptTimeAgo.locale(russian)

const timeAgo = new javascriptTimeAgo('ru')
timeAgo.format(new Date(Date.now() - 60 * 1000))
// "1 минуту назад"

Loading locales

No locales are loaded by default. This is done to allow tools like Webpack take advantage of code splitting to reduce the resulting javascript bundle size.

But server side doesn't need code splitting, so to load all available locales in Node.js one can use this shortcut:

// A faster way to load all localization data for Node.js
// (`intl-messageformat` will load everything automatically when run in Node.js)
require('javascript-time-ago/load-all-locales')

Customization

Localization data described in the above section can be further customized, for example, supporting long and short formats. Refer to locales/en.js for an example.

Built-in localization data is presented in different variants. Example:

import english from 'javascript-time-ago/locales/en'

english.tiny  // '1s', '2m', '3h', '4d', …
english.short // '1 sec. ago', '2 min. ago', …
english.long  // '1 second ago', '2 minutes ago', …

One can pass options as a second parameter to the .format(date, options) function. It's called a style (see twitter style for example). The options object can specify:

  • flavour – preferred labels style (e.g. tiny, short, long)
  • units – a list of time interval measurement units which can be used in the formatted output (e.g. ['second', 'minute', 'hour'])
  • gradation – custom time interval measurement units scale
  • override – is a function of { elapsed, time, date, now }. If the override function returns a value, then the .format() call will return that value. Otherwise it has no effect.

Gradation

A gradation is a list of time interval measurement steps. A simple example:

[
  {
    unit: 'second',
  },
  {
    unit: 'minute',
    factor: 60,
    threshold: 59.5
  },
  {
    unit: 'hour',
    factor: 60 * 60,
    threshold: 59.5 * 60
  },
  …
]
  • factor is a divider for the supplied time interval (in seconds)
  • threshold is a minimum time interval value (in seconds) required for this gradation step
  • (some more threshold customization is possible, see the link below)
  • granularity can also be specified (for example, 5 for minute to allow only 5-minute intervals)

For more gradation examples see source/classify elapsed.js

Available gradations:

import { gradation } from 'javascript-time-ago'

gradation.canonical()  // '1 second ago', '2 minutes ago', …
gradation.convenient() // 'just now', '5 minutes ago', …

Future

When given negative time intervals this library outputs future dates, like "in 5 minutes", "in a year", etc.

React

There is also a React component.

Contributing

After cloning this repo, ensure dependencies are installed by running:

npm install

This module is written in ES6 and uses Babel for ES5 transpilation. Widely consumable JavaScript can be produced by running:

npm run build

Once npm run build has run, you may import or require() directly from node.

After developing, the full test suite can be evaluated by running:

npm test

When you're ready to test your new functionality on a real project, you can run

npm pack

It will build, test and then create a .tgz archive which you can then install in your project folder

npm install [module name with version].tar.gz

License

MIT