Working with dates and localStorage example

scripts.js

var d1 = new Date();
var d2 = new Date();
localStorage.d1 = d1; // add to localStorage
localStorage.d2 = d2;
d1 = Date.parse(localStorage.d1); // pull from localStorage and parse to date object
d2 = Date.parse(localStorage.d2);
console.log(d2 - d1); // milliseconds elapsed between the two times. 

localStorage.clear(); // clear local storage

Useful if you want JavaScript to run after a set interval. For example, to run an animation only once per visit you might use this to make sure 24 hours has passed before running animation again.