Get difference between two dates. Number of seconds, minutes, hours and days between two unix timestamps.

difference-between-dates.js

var unixTimeBetween = function(d1, d2) {
  var today = d2.getTime() / 1000
  var diff = Math.abs(d1 - (d2.getTime() / 1000));
  
  var result = diff / (60 * 60 * 24);
  console.log('Result: ' + result);
  
  if(result * 24 * 60 * 60 < 60)
    console.log('Seconds ago: ' + Math.trunc(result * 24 * 60 * 60));
  else if(result * 24 * 60 < 60)
    console.log('Minutes ago: ' + Math.trunc(result * 24 * 60));
  else if(result < 1)
    console.log('Hours ago: ' + Math.trunc(result * 24));
  else
  	console.log('Days ago: ' + Math.trunc(result));
};

var d1 = 1579140511; // Some other Date (in the past)
var d2 = new Date(); // Today

unixTimeBetween(d1, d2);

See working demo (open console - F12): https://jsfiddle.net/jarbely/q6xorn97/