What's the simplest way to decrement a date in Javascript by 1 day?

Question

I need to decrement a Javascript date by 1 day, so that it rolls back across months/years correctly. That is, if I have a date of \'Today\', I want to get the date for \'Ye

Answer 1

 day.setDate(day.getDate() -1); //will be wrong

this will return wrong day. under UTC -03:00, check for

var d = new Date(2014,9,19);
d.setDate(d.getDate()-1);// will return Oct 17

Better use:

var n = day.getTime();
n -= 86400000;
day = new Date(n); //works fine for everything