openinghours.js

Given an opening hours structure as defined by schema.org/OpeningHoursSpecification, and as used by Google, this can tell you if at a particular point in time the entity is open, and when it will close, or the reverse.

This is still a work on progress and might fail to return the right result in edge cases, but seems to handle most common cases, and comes with a test suite.

Install

$ yarn add openinghours.js
$ npm install --save openinghours.js

Documentation

The data structure

Define your opening hours using this data structure:

const rules = [
  // This applies to every day
  {
    opens: '08:00',
    closes: '18:00'
  },
  {
    // This applies to any monday or tuesday.
    dayOfWeek: ['monday', 'tuesday'],
    // 00:00 - 00:00 means closed the whole day.
    opens: '00:00',
    closes: '00:00',
  },
  {
    // This applies to any sunday in December 2019
    dayOfWeek: ['sunday'],
    validFrom: '2019-12-01',
    validThrough: '2019-12-21',
    // 00:00 - 23:59 means open the whole day.
    opens: '00:00',
    closes: '23:59',
  },
];

The main query function

Query the state at a given point in time:

import {getCurrentState} from 'openinghours.js';

getCurrentState(
  rules,
  {
    date: new Date()
  }
);

The return value is an object such as:

const result = {
  isOpen: true,
  closesAt: new Date("2019-12-05T14:00:00.000Z")
}

const result = {
  isOpen: false,
  opensAt: new Date("2019-12-05T14:00:00.000Z")
}

A note on timezones

The library fully supports timezones.

To declare which timezone the open/close time rules refer to, you can pass a rulesTimezone option:

getCurrentState(
  [
    {
      opens: '08:00',
      closes: '18:00'
    }
  ],
  {
    date: new Date("2019-12-05T07:30:00"),
    rulesTimezone: 'Europe/Berlin'
  }
);

If you run the above on a GMT machine (so the time queried will be 07:30 GMT) while Europe/Berlin is GMT+1, then the result will be "is open", because the shop opened at 7am in GMT time (and at 8am in Europe/Berlin time).

It is strongly recommended that you pass this option, as the results you get will otherwise depend on the host machine timezone you run the query on: If not given, we assume 06:00 means 6am in the local timezone. If your code runs in a browser on a visitor's machine in America/New_York at 6am New York time, we'll assume the entity is just opening, which will not be true if it is situated in a different timezone.

For the date you want to query, you can pass a luxon.DateTime object instead of a native Date:

import {getCurrentState} from 'openinghours.js';
import {DateTime} from 'luxon';

getCurrentState(
  rules,
  {
    date: DateTime.fromObject({ hour: 10, minute: 26, second: 6, year: 2019, month: 5, day: 25, zone: 'America/New_York' }),
    rulesTimezone: 'Europe/Berlin'
  }
);

Other libraries

I could not find another library dealing with opening hours that does the following:

• Supports the data structure behind the schema.org specification.
• Can calculate when a business will next open or close.