<div class="post-date"><span class="post-month"><?php the_time('M') ?></span> <span class="post-day"><?php the_time('d') ?></span></div>

.post {
	clear:both;
	padding-top: 15px;
}
.post-date {
	width: 45px;
	height: 49px;
	float:left;
	background: url(images/date-bg.gif) no-repeat;
}
.post-month {
	font-size: 11px;
	text-transform: uppercase;
	color: #FFFFFF;
	text-align: center;
	display:block;
	line-height: 11px;
	padding-top: 2px;
	margin-left: -3px;
}
.post-day {
	font-size: 18px;
	text-transform: uppercase;
	color: #999999;
	text-align: center;
	display:block;
	line-height: 18px;
	padding-top: 7px;
	margin-left: -3px;
}
.post-title {
	float: left;
	margin-left: 10px;
	width: 430px;
}