How to get current timestamp using javascript?

You can create a function in Javascript 1.5 and above using Date.now()

var time = Date.now || function() {
  return +new Date;
};

//calling function
time();

To get the Unix timestamp you can use the below code

var UnixTimeStamp = Math.round((new Date()).getTime() / 1000);

the above code convert the current date and time to a UNIX timestamp, getTime() returns milliseconds from the UNIX epoch, so divide it by 1000 to get the seconds representation. It is rounded using Math.round() to make it a whole number.