How do i properly position absolute divs within twitters bootstrap css framework

Question

I can't seem to get a div to absolutely position within its parent using the twitter bootstrap framework. I have a series of rows that follow a scheme as follows

<div id='wrapper'>
<div class='row-fluid'>
    <div class='span2'>some content here</div>
    <div class='span9'>other content to the side of the first div</div>
    <div class='timestamp'>123456 this should align to the bottom right of wrapper</div>
</div>
</div>

css

.timestamp{
   position:absolute;
   bottom:0px;
   right:0px;
}

But the timestamp div always positions itself to the absolute of the body of the whole dom document ignoring any intermediate divs. Any ideas what is causing this?

Solution

Your css should include

 #wrapper {
    position: relative;
}

The default positioning is static.

check out this article: http://css-tricks.com/absolute-positioning-inside-relative-positioning/