Check out the css in blog_elements.css and edit font-size:##% as you wish...
Example css...

/* Calendar: */
table.bCalendarTable caption {
	font-size: 105%;
	font-weight: bold;
	margin: auto;
	padding: 3px 0;
	white-space: nowrap;
}
table.bCalendarTable {
	margin: 0 auto 1em auto;
	font-size: 77%;
	border-collapse: separate;
	border-spacing: 0px;
}
tr.bCalendarRow {
	text-align: center;
}
th.bCalendarHeaderCell {
	color: #999;
	font-size: 84%;
	width: 4ex;
}
td.bCalendarCell,
td.bCalendarLinkPost,
td.bCalendarEmptyCell {
	width: 4ex;
	padding: 2px 0;
}
.bCalendarLinkPost {
	font-weight: bold;
}
#bCalendarToday {
	background-color: #f6eeee;
	border: 1px solid #900;
}

hey, thanks a million!