js why cant i use Date code example

Example 1: Javascript format date / time

var date = new Date('2014-8-20');
console.log((date.getMonth()+1) + '/' + date.getDate() + '/' +  date.getFullYear());

Example 2: how to tell this x = 12 + 30 when i read it in js

var x = Math.floor(Math.random() * (max - min + 1)) + min;