javascript date creation, can't set the correct month

Question

var d = new Date(2011,1,1);

alert(d);

this alert says February, while it should say January

anybody has some explanation for that ?

Answer 1

the month argument is zero based. So 0 = jan, 1 = feb, etc....

Look here. Specifically at the part that says

The setMonth() method sets the month (from 0 to 11), according to local time.

Note: January is 0, February is 1, and so on.