@qntm-code/string-to-date

Parse a wide range of date formats including human-input dates.

Installation

npm install string-to-date

or

yarn add string-to-date

Table of Contents

• @qntm-code/string-to-date
  • Installation
  • Table of Contents
  • Usage
  • Supported formats
  • Locale Support
  • Adding custom formats
    • Example 1: matcher + units
    • Example 2: matcher + handler
    • Example 3: template + units
    • Example 4: template + handler
    • Removing parsing rules
    • Creating a custom parser
  • Unit tests
    • Testing
  • Contributing
  • Exhaustive list of date formats
  • Credits

Usage

There are two ways to use string-to-date:

1.) Return a Date object.

parse() arguments:

argument	type	description	optional
input	string	The string to parse	no
locale	string	The locale to use	yes

Example:

import StringToDate from 'string-to-date';

StringToDate.parse('2020-10-15');
// same as new Date(2020, 9, 15, 0, 0, 0, 0)

If the string cannot be parsed, null is returned.

2.) Return an object with one or more integer values for the following keys: year, month, day, hour, minute, second, millisecond, offset.

parseToObject() arguments:

argument	type	description	optional
input	string	The string to parse	no
locale	string	The locale to use	yes

Example:

import StringToDate from 'string-to-date'

StringToDate.parseToObject('15 Oct 2020 at 6pm');
// returns:
{
  year: 2020,
  month: 10,
  day: 15,
  hour: 18,
}

If the string cannot be parsed, null is returned.

Supported formats

Summary:

• 24 hour time
• 12 hour time
• timezone offsets
• timezone abbreviations
• year month day
• year monthname day
• month day year
• monthname day year
• day month year
• day monthname year
• +/-/ago periods
• now/today/yesterday/tomorrow
• Twitter

Exhaustive list of date formats

Locale Support

string-to-date supports any locale that your runtime's Intl (ECMAScript Internationalization API) supports. In browsers that usually means the operating system language. In Node, that means the compiled language or the icu modules included.

Adding custom formats

string-to-date has an addFormat() function to add a custom parser.

First, parsers must have matcher or template.

• matcher: A RegExp to match a string
• template: A string with template variables such as _YEAR_ _MONTH_ etc. that will be converted to a regular expression

Second, parsers must have units or handler.

• units: An array of unit strings to fit matches into (year, month, day, etc.)
• handler: A function that takes matches and returns an object with keys year, month, day etc.

Example 1: matcher + units

import StringToDate from 'string-to-date';

parser.addFormat(
  new Format({
    matcher: /^(\d+) days? into month (\d+) in year (\d{4})$/,
    units: ['day', 'month', 'year'],
  })
);

Keep in mind that \d does not support other numbering system such as Chinese or Bengali. To support those you can use the template option given in example 3 and example 4.

Example 2: matcher + handler

import StringToDate from 'string-to-date';

parser.addFormat(
  new Format({
    matcher: /^Q([1-4]) (\d{4})$/,
    handler: function ([, quarter, year]) {
      const monthByQuarter = { 1: 1, 2: 4, 3: 7, 4: 10 };
      const month = monthByQuarter[quarter];
      return { year, month };
    },
  })
);

Example 3: template + units

import StringToDate from 'string-to-date';

parser.addFormat(
  new Format({
    template: 'The (_DAY_)(?:_ORDINAL_) day of (_MONTH_), (_YEAR_)',
    units: ['day', 'month', 'year'],
  })
);

Example 4: template + handler

import StringToDate from 'string-to-date';

parser.addFormat(
  new Format({
    template: '^Q([1-4]) (_YEAR_)$',
    handler: function ([, quarter, year]) {
      const monthByQuarter = { 1: 1, 2: 4, 3: 7, 4: 10 };
      const month = monthByQuarter[quarter];
      return { year, month };
    },
  })
);

Removing parsing rules

To remove support for a certain format, use removeFormat()

import StringToDate, { dayMonth } from 'string-to-date';

parser.removeFormat(dayMonth);

Creating a custom parser

To create a new parser with a limited list of formats or your own custom formats, use new Parser

import { Parser, time24Hours, yearMonthDay, ago } from 'string-to-date';

const parser = new Parser();

parser.addFormats([time24Hours, yearMonthDay, ago]);

Unit tests

Testing

• To run tests, run npm test

Contributing

Contributions are welcome. Please open a GitHub ticket for bugs or feature requests. Please make a pull request for any fixes or new code you'd like to be incorporated.

Exhaustive list of date formats

24 hour time (any date format followed by a 24-hour time expression)

• 2020-10-06 17:41:28
• 2020-10-06T17:41:28Z
• 17:41:28
• 2020-10-06T17:41:28.999Z
• 2020-10-06T17:41:28.999999Z
• 2020-10-06T17:41:28.999999999Z
• 2020-10-06T17:41:28 MST
• 2020-10-06T17:41:28 Eastern Daylight Time
• 2020-10-06T17:41:28 GMT+03:00
• 2020-10-06T17:41:28 GMT-9
• 2020-10-06T17:41:28-09:00
• 2020-10-06T17:41:28+0900

12 hour time (any date format followed by a 12-hour time expression)

• March 14, 2015 at 9:26:53 am
• 14 Mar 2015 9:26:53 a.m.
• 9:26:53am
• 9:26pm
• 9pm

day monthname year

• Wednesday, 01 January 2020
• Wednesday 01 January 2020
• Wed, 01 January 2020
• Wed 01 January 2020
• 01 January 2020
• 01-January-2020
• 1 Jan 2020
• 1-Jan-2020
• 01 Jan 20
• 1 Jan 20

monthname day year

• Sunday, March 27 2016
• Sunday March 27 2016
• Sun, March 27 2016
• Sun March 27 2016
• March 27 2016
• Mar 27, 2016
• Mar 27 2016

month day year

• 03/14/2020
• 03-14-2020
• 03.14.2020
• 03 14 2020
• 3/14/2020
• 3-14-2020
• 3.14.2020
• 3 14 2020
• 03/14/20
• 03-14-20
• 03.14.20
• 03 14 20
• 3/14/20
• 3-14-20
• 3.14.20
• 3 14 20

day month year

• 14/03/2020
• 14.03.2020
• 14-03-2020
• 14 03 2020
• 14/3/2020
• 14.3.2020
• 14-3-2020
• 14 3 2020
• 14/03/20
• 14.03.20
• 14-03-20
• 14 03 20
• 14/3/20
• 14.3.20
• 14-3-20
• 14 3 20

year month day

• 2016/09/24
• 2016/09/24
• 2016/9/24
• 2016/9/24
• 16/09/24
• 16/09/24
• 16/9/24
• 16/9/24
• 2016-09-24
• 2016-09-24
• 2016-9-24
• 2016-9-24
• 16-09-24
• 16-09-24
• 16-9-24
• 16-9-24
• 2016 09 24
• 2016 09 24
• 2016 9 24
• 2016 9 24
• 16 09 24
• 16 09 24
• 16 9 24
• 16 9 24
• 2016.09.24
• 2016.09.24
• 2016.9.24
• 2016.9.24
• 16.09.24
• 16.09.24
• 16.9.24
• 16.9.24
• 20160924
• 20160924
• 2016924
• 2016924
• 160924
• 160924
• 16924
• 16924

relative time

• 5 minutes ago
• -8 months
• in 13 days
• +21 weeks

monthname day

• Sunday, June 28
• Sunday June 28
• Sun, June 28
• Sun June 28
• June 28
• Jun 28

day monthname

• 16 March
• 16 Mar

month day

• 03/14
• 03-14
• 3/14
• 3-14

day month

• 14/03
• 14.03
• 14/3
• 14.3

Twitter

• Fri Apr 09 12:53:54 +0000 2010

unix timestamp

• @1602604901

Microsoft JSON date string

• /Date(1601677889008-0700)/
• /Date(1601677889008)/

chinese

• 2020年09月26日
• 2020年9月26日
• 2020 年 9 月 26 日
• ２０１７年０８月３１日

Credits

This package is based on any-date-parser by Ken Snyder