updated_time
is the UNIX timestamp
In PHP you can use strtotime
-
strtotime("-3 month") //3 months ago
strtotime("now") //now
In Javascript-
var d = new Date();
d.setMonth(d.getMonth() - 3);
Math.round(d.getTime() / 1000); //3 months ago
Math.round((new Date()).getTime() / 1000); //now