npm install twix

Another range plugin is Isaac Cambron's library Twix. It has many range-related features and excels at formatting ranges readably. For example,

var t = moment("1/25/1982 9:30 AM").twix("1/25/1982 1:30 PM");
t.isCurrent(); // false
t.count('minutes'); // 241
t.format();  // 'Jan 25, 1982, 9:30 AM - 1:30 PM'
t.simpleFormat("h:m"); // '9:30 - 1:30'

Full documentation of all the options and features is here.

It's available on npm like so:

npm install twix

Or just grab the JS file from here.