Untitled

<html>
<head>
    <style>
        .imageContainer {
            background-image:url('calenderPic.jpg');
            background-position:center;
            background-repeat:none;
        }

        .textContainerWithinImage {
            position:relative; /* relative to imageContainer */
            margin:auto; /* *should* vertically/horizontally center your text */
            color:white;
            font-weight:bold; /* so text stands out */
        }
    </style>

    <script type="PsuedoJavaScript">
        dateOfPost = functionToLoadPostData();
        getElementById('textContainerWithinImage').innerHTML = dateOfPost;
    </script>
</head>

<body>
    <div id="imageContainer">
        <div id="textContainerWithinImage">Text will be shown on top of image.</div>
    </div>
</body>

</html>