README

iso-datestring-validator

What is it

A simple package for validating strings denoting dates and time, including ISO 8601 format. The package provides the following functions:

Date validation. YYYY-MM-DD format from 0001-01-01 to 9999-12-31, leap year friendly. Custom digit separators and null separators supported: YYYY/MM/DD or YYYYMMDD is no problem.
Time validation. HH:mm:ss.fff±hh:mm format, seconds, fractions of seconds and timezone offset being optional. Custom digit separators supported for HHmmss as well (no custom separator for fractions, it is dot).

Caveat: do not use '-' and '+' as separators when validating time with timezone. I am reluctant to fix this unless it is an issue.

isValidTime('14-45-15.000+00-00', '-', true);
// will yield wrong result

Year-month validation.
ISO 8601 datestring validation with timezones, with and without separators:

2019-07-09T15:03:36.000+00:00
2019-07-09T15:03:36Z
20190709T150336Z

Installation

npm i --save iso-datestring-validator

yarn add iso-datestring-validator

Import

import * as isoDatestringValidator from 'iso-datestring-validator';

alternatively you can import the function that you need separately:

import {
  isValidDate,
  isValidISODateString,
  isValidTime,
  isValidYearMonth,
} from 'iso-datestring-validator';

Usage

Date validation

Pass a YYYY-MM-DD date string to the isValidDate function to check it. To validate dates that use a custom digit separator, pass it as the second argument.

import { isValidDate } from 'iso-datestring-validator';

isValidDate('2019-01-31');
// true

isValidDate('20190131');
// false, no custom digit separator provided, hyphen separator not found in the string

isValidDate('20190131', '');
// true

isValidDate('2019/01/31', '/');
// true

Time validation

Time string in HH:mm:ss.fff±hh:mm format can be validated with the isValidTime function. Seconds and fractions are optional. However, if using fractions min number of numbers is 1 and max is 9. Zone offset is optional as well, its check is switched off by default.

import { isValidTime } from 'iso-datestring-validator';

isValidTime('13:00');
// true

isValidTime('13:00:00');
// true

isValidTime('13:00:00.000000000');
// true

// pass time, separator and boolean flag to enable zone offset check
isValidTime('14:45:15.000+00:00', ':', true);
// true

// you can take advantage of default separator if you pass undefined as second param
isValidTime('14:45:15.000+00:00', undefined, true);
// true

isValidTime('144515.000Z', '', true);
// true

Year and month validation

These are validated by the isValidYearMonth function. Rules same as in the previous case: a string YYYY-MM and a custom digit separator if required.

import { isValidYearMonth } from 'iso-datestring-validator';

isValidYearMonth('2019/01', '/');
// true

isValidYearMonth('2019-01');
// true

ISO 8601 datestring validation

Pass a string to isValidISODateString to see if it is valid.

import { isValidISODateString } from 'iso-datestring-validator';

isValidISODateString('2019-07-09T15:03:36.000+00:00');
// true

isValidISODateString('20190709T150336Z');
// true

That's all about this package. Have fun, feel free to contribute with some test :]

Usage no npm install needed!