A JavaScript function to convert Unix time (milliseconds since 1 Jan 1970 at 00:00:00) to a Qlik time (days since 30 Dec 1899 at 00:00:00). Correct to the nearest second.

unixToQlikTime.js

/*
| -------------------------------------------------------------------
|  Unix to Qlik time 
| -------------------------------------------------------------------
|  Convert a unix timestamp to a Qlik timestamp.
|
*/
var unixToQlikTime = function(){
    a      = new Date(1899,12,30);  //this is Qlik's Epoch date (http://help.qlik.com/en-US/qlikview/12.1/Subsystems/Client/Content/Scripting/DateAndTimeFunctions/date-time-functions.htm).
    b      = new Date();

    var utc1 = Date.UTC(a.getFullYear(), a.getMonth(), a.getDate());
    var utc2 = Date.UTC(b.getFullYear(), b.getMonth(), b.getDate());
    var time = ((b.getHours() * 60 * 60) + (b.getMinutes() * 60) + b.getSeconds()) *1000 / (24*60*60*1000);
    return ((utc2 - utc1) /(24*60*60*1000))+time;
};