date-duration

Manipulate Date objects with ISO 8601-formatted durations.

Installation

$ npm install date-duration

Usage

import Duration from 'date-duration';

let duration = Duration('PT1H');
// or
let duration = Duration({P: {T: {H: 1}}});

Note: keep in mind that working with time-only durations (hours, minutes, seconds) is generally a better idea.

A duration of PT36H is not the same as P1DT12H. The former will add/subtract exactly 36 hours while the latter will add 12 hours + whatever 1 day means. e.g. if jumping across DST (Daylight saving time) and the difference is 1 hour, this totals to plus/minus 35 hours or 37 hours.

This is generally what you want as long as you take into account this happens within the context of the timezone of your environment. This can become tricky when used in browsers (where you don't have control over this).

API

Duration(ISOString)

Pass a string in ISO 8601 duration format to create a duration.

duration.addTo(Date)

Add the duration to a Date object and returns the new date. Objects with a .toDate() (like Moment.js) method are converted to a regular Date object.

duration.subtractFrom(Date)

Subtract the duration from a Date object and returns the new date. Objects with a .toDate() method are converted to a regular Date object.

duration.add(Duration)

Add durations together returning a new duration which is the sum of both.

duration.multiply(number)

Multiply individual parts of duration returning a new duration as the result.

duration.toString()

Convert a duration to a string in ISO 8601 format.