Add the time of working code – javascript

How to add time display with seconds to this working date code. Time should be shown UTC +1. And is it possible for it to automatically switch to winter and summer time?

Unfortunately, I don’t understand script programming.
Here is the working code that I have

var d = new Date();
var day=new Array("Sunday", "Monday", "Tuesday", "Wednesday", "Thursday", "Friday", "Saturday");
var month=new Array("January", "February", "March", "April", "May", "June", "July", "August", "September", "October", "November", "December");
document.write(day[d.getDay()]+" " +d.getDate()+ " " + month[d.getMonth()]
                        + " " + d.getFullYear() + " Year.");