显示日期分为日-月-年以及以下日期的组合

我正在尝试在HTML页面中使用当前的月，年，月-年和日-月。

这是我正在使用的javascript

var months = ["January", "February", "March", "April", "May", "June", "July", "August", "September", "October", "November", "December"];
var n = new Date();
var y = n.getFullYear();
var m = n.getMonth();
var d = n.getDate();
document.getElementById("date").innerHTML = d + " " + months[m] + " " + y;
document.getElementById("month-year").innerHTML =  months[m] + " " + y;
document.getElementById("day-month").innerHTML = d + " " + months[m];
document.getElementById("year").innerHTML = y;
document.getElementById("month").innerHTML = months[m];
document.getElementById("day").innerHTML = d;

I'm using an html <a> tag to call the date, month, year etc, as follows

<a id="date"></a>
<a id="month-year"></a>
<a id="day-month"></a>
<a id="year"></a>
<a id="month"></a>
<a id="day"></a>

However it only works when I use <a id="date"></a> somewhere in the page, if I don't use <a id="date"></a> then none of the other tags work.

I've created a jsfiddle to highlight the problem. If you remove <a id="date"></a> from the Html section you'll see the problem I'm referring to.