To set the month value using Coordinated Universal Time (UTC), use the setUTCMonth method.
If the value of numMonth is greater than 11 (January is month 0) or is a negative number, the stored year is modified accordingly. For example, if the stored date is "Jan 5, 1996" and setMonth(14) is called, the date is changed to "Mar 5, 1997."
function SetMonthDemo(newmonth){
var d, s; //Declare variables.
d = new Date(); //Create Date object.
d.setMonth(newmonth); //Set month.
s = "Current setting is ";
s += d.toLocaleString();
return(s); //Return new setting.
}