Add number of days to date in javascript

var CurrentDate = new Date();
var numberOfDaysToAdd = 6;
CurrentDate.setDate(CurrentDate.getDate() + numberOfDaysToAdd); 

Add number of months to date in javascript

var CurrentDate = new Date();
var numberOfMonthsToAdd = 12;
CurrentDate.setMonth(CurrentDate.getMonth() + numberOfMonthsToAdd);

Add number of minutes to date in javascript

var twentyMinutesLater = new Date();
twentyMinutesLater.setMinutes(twentyMinutesLater.getMinutes() + 20);

<script>
var d = new Date();
var date_var = d.getFullYear()+'-'+d.getMonth()+'-'+d.getDate()+' '+d.getHours()+':'+d.getMinutes()+':'+d.getSeconds();
// format year-month-day hours:minutes:seconds
alert(date_var); // return '2012-10-25 10:45:37'
</script>