Timestamp to date with Javascript. How?

I create a timestamp with开发者_开发知识库 strtotime php function. My question is how to "reverse" timestamp to year, month, date, ... seconds etc using javascript ?

var date = new Date(phptimestamp*1000);
var hours = date.getHours();
var minutes = date.getMinutes();
var seconds = date.getSeconds();
//etc...

var date = new Date(seconds*1000);

where milliseconds is seconds since Jan 1970.

var date = new Date(timestamp*1000);