The calendar area you have circled can be positioned there using absolute positioning. Absolutely positioning a div will make it "float" on top of the page allowing for anything else to take up the space it leaves behind. So the content area would need some right padding to push it over to the left so it wouldn't get lost under the calendar area.
The wrapper div would have position: relative defined and the calendar div would have position: absolute defined and you will need to define top and right to position it to your liking.
The other thing to point out is that the screenshot shows the calendar div floating over the footer area. If there was more content to the page, making the page grow vertically, then the calendar div would stay positioned where it was and it wouldn't still float over the footer because the page height grew.
If you need a tutorial on absolute positioning I have one available
here.