How to get month list in your locale
#javascript#typescript#localization#webdev
Maksim

Maksim @pretaporter

About: Creator and maintainer of https://github.com/ibitcy/eo-locale | Contributor of https://github.com/renovatebot/renovate | Son, husband and cat owner.

Location:
Amsterdam, Netherlands
Joined:
Mar 19, 2019

How to get month list in your locale

Publish Date: Jun 4 '20
56 11

Hi there! I am glad to show simple TypeScript function, that maybe will save your time. In many cases you need to implement selector of months. In some cases it should be in different locales. See it below:

function getMonthList(
  locales?: string | string[],
  format: "long" | "short" = "long"
): string[] {
  const year = new Date().getFullYear(); // 2020
  const monthList = [...Array(12).keys()]; // [0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11]
  const formatter = new Intl.DateTimeFormat(locales, {
    month: format
  });

  const getMonthName = (monthIndex: number) =>
    formatter.format(new Date(year, monthIndex));

  return monthList.map(getMonthName);
}
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That's it. Just provide your locale as param.
For example, 🇬🇧 getMonthList('en') will return:

January
February
March
April
May
June
July
August
September
October
November
December
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Try it by yourself on codesandbox.

For short version of names just provide second param as short.
For example, 🇬🇧 getMonthList('en', 'short') will return:

Jan
Feb
Mar
Apr
May
Jun
Jul
Aug
Sep
Oct
Nov
Dec
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Update
By your requests I have extracted function in package

Comments 11 total

  • Maksim
    MaksimJun 4, 2020

    Thanks, fixed

  • asdsadasf
    asdsadasfJun 9, 2020

    Hi, great article, thanks.

    Which part of this code is typescript, It's like all javascript to me, but some parts seems strange. Maybe those parts, lol?

    • Maksim
      MaksimJun 9, 2020

      Thank you! JavaScript version:

      function getMonthList(locales, format = "long") {
  const year = new Date().getFullYear(); // 2020
  const monthList = [...Array(12).keys()]; // [0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11]
  const formatter = new Intl.DateTimeFormat(locales, {
    month: format
  });

  const getMonthName = (monthIndex) =>
    formatter.format(new Date(year, monthIndex));

  return monthList.map(getMonthName);
}
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      • Danny Engelman
        Danny EngelmanJun 9, 2020

        Using the 2nd parameter mapFn on Array.from instead of .map saves a spread on monthList

        function getMonthList(locales, format = "long") {
  const year = new Date().getFullYear(); // 2020
  const monthList = Array(12).keys(); // an Array Iterator
  const formatter = new Intl.DateTimeFormat(locales, {
    month: format
  });
  const getMonthName = (monthIndex) =>  formatter.format(new Date(year, monthIndex));

  return Array.from(monthList , getMonthName);
}

```

`
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        • Danny Engelman
          Danny EngelmanJun 9, 2020

          And since year is not a parameter, no need for const year declaration to get a monthname

          new Date(0, monthIndex) will do, for ES Arrow function:

          const getMonthList = (locale = "en", notation = "long" ) =>
  Array.from(
    Array(12).keys(),
    key => Intl.DateTimeFormat(locale, {
      month: {
         s : "short",
         n : "numeric"
      } [notation[0]] || "long"
    })
    .format(new Date(0, key))
  );
```

`
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          • Maksim
            MaksimJun 9, 2020

            Cool, thanks!

            For constructor of Intl.DateTimeFormat locales is optional param. No requirement to provide default value of locale.

  • Maksim
    MaksimJun 9, 2020

    Amazing work!

  • Mark Valentine
    Mark ValentineDec 31, 2020

    Sorry I know this is a bit of an old thread but I can't find an answer via google. Could someone please explain line 8 of Danny Engleman's 2nd post.

    I get that it is creating an object as the 2nd parameter to "DateTimeFormat" with 1 attribute named "month" that maps to another object.

    What does [notation[0]] || "long" do? To me it looks like it should be a 2nd attribute of the outer object, but in my mind it should have a comma.

    Thank you in advance.

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