This is untested, bu should work:
<script>
//set a limit date
//Date constructor new Date( year, month, day, hour, minutes, seconds )
var contDates = new Array(
new Array("content",new Date( 2006, 3, 14, 12, 10, 0 )),
new Array("content2",new Date( 2006, 3, 14, 12, 10, 0 )),
new Array("content3",new Date( 2006, 3, 14, 12, 10, 0 )),
new Array("content4",new Date( 2006, 3, 14, 12, 10, 0 ))
);
//date comparison is implemented in Javascript, so,
//you'll just need to show the layer if current date in smaller than limitDate
function showContent(){
for (var i=0; i<contDates.length; i++) {
if ( new Date() < contDates[i][1]){
document.getElementById(contDates[i][0]).style.visibility = "visible"
}
}
}
</script>
At the top, there are four content-date pairs, and should be easy enough to add more, based on the pattern there.
--Steve