Working Days documentation

This package is an example of legislation as code, and can be used to determine whether or not a given day qualifies as a working day, as defined in the legislation of Aotearoa New Zealand.

Methods

isWorkingDay

isWorkingDay(date: Date, definition: WorkingDayDefinition = WorkingDayDefinition.OIA) => boolean

Determines whether or not a given date qualifies as a working day, for a given definition. By default, the definition of working day used by the Official Information Act 1982 will be used.

Arguments

`date: Date`

A Date that may or may not be a working day. Only the year, month, and day portion of the Date will be used.

`definition: WorkingDayDefinition`

The definition of working day to use in the determination. If this argument is ommitted, the definition used by the Official Information Act 1982 will be used.

Limitations

Some definitions of days which are not working days under the Official Information Act 1982 are not defined outside certain date ranges.

Sovereign's Birthday

Dates in the year 1953, or prior to 1952, will throw a RangeError due to a lack of a definition for the Sovereign's Birthday.

This date is also defined for years after 1953 only in respect of every year of the reign of Her Majesty Queen Elizabeth the Second. Elizabeth II died in September 2022, so until the Sovereign's Birthday Observance Act 1952 is amended there is no defined date for the sovereign's birthday observance day in years after 2022.

Matariki

The dates of Matariki are, at the time of writing, defined only up to the year 2052. Dates from 2053 onward will throw a RangeError due to a lack of a definition for Matariki.

Easter

The method used for calculating Easter dates is only correct for the years 1900-2199. Dates outside this range will throw a RangeError.

Examples

Select a date to see whether or not it is considered a working day according to the definition under the Official Information Act 1982.

workingDaysBetween

workingDaysBetween(startDate: Date, endDate: Date, definition: WorkingDayDefinition = WorkingDayDefinition.OIA) => number

Counts the number of working days between two dates, for a given definition. By default, the definition of working day used by the Official Information Act 1982 will be used.

Arguments

`startDate: Date`

The first Date in a range to count working days between.

`endDate: Date`

The last Date in a range to count working days between.

`definition: WorkingDayDefinition`

The definition of working day to use in the determination. If this argument is ommitted, the definition used by the Official Information Act 1982 will be used.

addWorkingDays

addWorkingDays(startDate: Date, numWorkingDays: number, definition: WorkingDayDefinition = WorkingDayDefinition.OIA) => number

Determines what the date will be after a specified number of working days from a start date, for a given definition of working day. By default, the definition of working day used by the Official Information Act 1982 will be used.

Arguments

`startDate: Date`

The Date from which to start.

`numWorkingDays: number`

The number of working days to count after the starting date.

`definition: WorkingDayDefinition`

The definition of working day to use in the determination. If this argument is ommitted, the definition used by the Official Information Act 1982 will be used.

getHoliday

getHoliday(holiday: Holiday, year: number): DateTuple | null

Returns the specified holiday for the specified year.

Some holidays, such as Mondayised Anzac Day, may not exist in each year. In these cases, this function can return null.

Other holidays have specific restrictions under which they will throw errors. For example, Matariki is not currently defined for years after 2052, so attempting to get the date of Matariki after 2052 will throw a RangeError.

Arguments

`holiday: Holiday`

The holiday you want to retrieve, specified using the Holiday enum exported by this package.

`year: number`

The year in which you want to get the date of the specified holiday.

Interfaces

DateTuple

type DateTuple = [
	number, // year
	number, // month
	number, // day
];

The DateTuple interface is used in place of Date to refer to just the date portion of a Date, ignoring any time or regional information.

The three numbers correspond with the values that would be returned by Date.getFullYear(), Date.getMonth(), and Date.getDate(), respectively.

A Date can be constructed from a DateTuple if required via new Date(...tuple)

Enums

WorkingDayDefinition

enum WorkingDayDefinition {
	OIA,
}

This enum's members can be used when calling isWorkingDay to specify a definition of working day to be used.

Currently, only the definition used by the Official Information Act 1982 is supported.

Holiday

enum Holiday {
	ANZAC_DAY,
	ANZAC_DAY_MONDAYISED,
	WAITANGI_DAY,
	WAITANGI_DAY_MONDAYISED,

	GOOD_FRIDAY,
	EASTER_SUNDAY,
	EASTER_MONDAY,

	LABOUR_DAY,
	MATARIKI,
	SOVEREIGNS_BIRTHDAY,

	QUEEN_ELIZABETH_II_MEMORIAL_DAY,
}

This enum's members can be used when calling getHoliday to specify a holiday to get the date of.