Pad Zeros : add leading zero to seconds, minutes, months and dates

padzero.js

var padZero = function(v) {
    return ('0'+v).split('').reverse().splice(0,2).reverse().join('');
}
// OR
var padZero = function(v){
    return ('0'+v).substr(-2);
}
    
padZero(6)  // 06
padZero(13) // 13