intervalsJS

intervalsJS is a node.js module for working with intervals. This library can be useful any time you find yourself working with intervals of numbers, strings or even dates. Documentation.

Installation

To install intervalsJS into your npm project, run the command

npm install intervals-js --save

A brief example

Imagine, you are building a calendar and you want to be able to display all weeks that overlap with the current month. This is a trivial task when using intervalsJS!

First, make sure you require intervalsJS

const intervalsJS = require('intervals-js');

Then, using a DateRange we can get a range representing January in the year 2000.

const month = new intervalsJS.DateRange().fromDate('2000-01-01', 'month');

Next, we can easily calculate the weeks which contain the first, and last day of the month.

const startWeek = new intervalsJS.DateRange().fromDate(month.lower, 'week');
const endWeek = new intervalsJS.DateRange().fromDate(month.upper, 'week');

Then using the union method, we can find all the days to display on our calendar

const display = month.union(startWeek).union(endWeek);

Huge thanks to Andreas Runfalk for not only inspiring me but also providing valuable feedback along the way. Heavy inspiration for how the implementation should run was taken from his python library spans.