Give him a date, it will return a path.
npm install date-pathCan be used on browser directly, with dist/date-path.min.js.
const datePath = require('date-path');
console.log(datePath(new Date(2017, 1, 12)));
// > 2017/02/
console.log(datePath(new Date(2016, 11, 20)));
// > 2016/12/
// By default it is today's date (and today is March 22th of 2017)
console.log(datePath());
// > 2017/03/