Determines whether a given date and time is on a weekend or a public holiday in the U.S. Can also add business days to a specified date to calculate a new date.

This package uses dayjs and date-holidays.

npm i business-days-js

First initialize a businessDays object:

import businessDays from "business-days-js";

const bDays = businessDays();

By default, businessDays treats 11 U.S. public holidays as non-business days. To use state-specific public holidays, instead initialize businessDays with an appropriate two-letter state abbreviation:

import businessDays from "business-days-js";

const bDays = businessDays({state: "pa"}); // use public holidays for Pennsylvania

Check out the docs for date-holidays for a full list of state abbreviations. Consult 'advanced usage' in this README for more information about customizing holidays.

To check whether a native Date object is a business day:

import businessDays from "business-days-js";

const bDays = businessDays({state: "pa"});
const presidentsDay = new Date("2016-02-15 00:00:00 GMT-0500"); // 12 a.m. on Feb. 15, 2016 (EST)
bDays.check(presidentsDay); // returns false

Dates can also be provided as a string formatted as "YYYY-MM-DD":

import businessDays from "business-days-js";

const bDays = businessDays({state: "pa"});
const bizDay = "2021-11-17"; // Wednesday, Nov 17, 2021
bDays.check(bizDay); // returns true

Or dates can be provided as a Day.js object:

import businessDays from "business-days-js";
import dayjs from "dayjs";

const bDays = businessDays({state: "pa"});
const xmasDay = dayjs("2020-12-25 00:00:00 GMT-0500"); // 12 a.m. on Dec 25, 2020 (EST)
bDays.check(xmasDay); // returns false

Add a specified number of business days to a date to calculate a new date. The returned date is a Day.js object.

import businessDays from "business-days-js";

const bDays = businessDays({state: "pa"});
const startDate = new Date("2020-12-20 00:00:00 GMT-0500");
bDays.addDays(startDate, 5) // returns a Day.js object representing Dec 28, 2020.

As with other methods, dates can be provided as a Day.js object or a string formatted as "YYYY-MM-DD":

import businessDays from "business-days-js";

const bDays = businessDays({state: "pa"});
const newDate = bDays.addDays("2020-12-20", 5) // returns a Day.js object representing Dec 28, 2020.

To return an object with a tally of total days, business days, weekends, weekdays, and holidays between two dates:

import businessDays from "business-days-js";

const bDays = businessDays({state: "pa"});
bDays.countDays("2020-12-20", "2020-12-28") // returns an object

Note that countDays excludes the start date from its calculations by default. For instance, by default countDays would count a total of eight days between "2020-12-20" to "2020-12-28" rather than nine days.

To include the start date in the tallies:

import businessDays from "business-days-js";

const bDays = businessDays({state: "pa"});
bDays.countDays("2020-12-20", "2020-12-28", {excludeInitialDate: false})

To get a list of public holidays for a specific year with the dates they end and start:

import businessDays from "business-days-js";

const bDays = businessDays({state: "pa"});
// returns an array of objects with data on Pennsylvania public holidays in 2020
bDays.getHolidays("2020") 

You can exclude specific public holidays from businessDays default list of public holidays. Simply initialize a businessDays object with a list of holidays to exclude.

import businessDays from "business-days-js";

const bDays = businessDays({state: "pa", excludeHolidays: ["Flag Day", "Presidents' Day"]});

// Flag Day and Presidents' Day will now be considered business days if they fall during the work week.
const flagDay = new Date("2019-06-14 00:00:00 GMT-0500")
const presDay = new Date("2020-02-17 00:00:00 GMT-0500")
bDays.check(flagDay) // returns true
bDays.check(presDay) // returns true

You can also add custom holidays to to the default list. Each custom holiday is an object with a 'name' property and a 'rule' property. The rule defines the occurrence of the holiday based on the grammar of date-holidays.

import businessDays from "business-days-js";

const CUSTOM_HOLIDAYS = [
  {
    rule: "02-02",
    name: "Groundhog Day",
  },
  {
    rule: "07-15",
    name: "Saint Swithin's Day",
  },
]
const bDays = businessDays({
  state: "pa",
  excludeHolidays: ["christmas day", "presidents' day"],
  addHolidays: CUSTOM_HOLIDAYS,
});

By default, when initialized without a state abbreviation, businessDays handles the following 11 U.S. public holidays as non-business days:

• New Year's Day
• Martin Luther King Jr. Day
• Washington's Birthday
• Memorial Day
• Juneteenth
• Independence Day
• Labor Day
• Columbus Day
• Veterans Day
• Thanksgiving Day
• Christmas Day

If those days fall on a weekend, substitution days are used based on rules defined by date-holidays. For instance, if Christmas Day (Dec 25) falls on a Sunday, then Monday will be assumed to be a public holiday. If Christmas Day falls on a Saturday than Friday will be assumed to be a public holiday.

For more information about holiday rules, consult the documentation for date-holidays.

If you find any bugs or have any suggestions for improvements, please feel free to open an issue or submit a pull request. Contributions are welcome!

business-days-js is licensed under the MIT License. See the LICENSE file for more information.