location.href not returns page
use correctly .load() method
$("#detailsRefreshCont").load("datetime.html");
or: HTML
<div class="linkText" id="detailsRefreshCont" >
<span id="datetime">
@DateTime.Now.ToString("MMMM dd"), @DateTime.Now.ToString("H:mm")
</span>
<span class="linkText" id="refreshDetails">Refresh</span>
JAVASCRIPT
$('#refreshDetails').click(function () {
loadDetailsData();
var now = new Date(), date = now.getDate(), month = now.getMonth(), weekday=new Array(7), namemonth = new Array(12),day = now.getDay(), hour = now.getHours(), minute = now.getMinutes();
namemonth[0]="January";
namemonth[1]="February";
namemonth[2]="March";
namemonth[3]="April";
namemonth[4]="May";
namemonth[5]="June";
namemonth[6]="July";
namemonth[7]="August";
namemonth[8]="September";
namemonth[9]="October";
namemonth[10]="November";
namemonth[11]="December";
day -= 1;
weekday[0]="Monday";
weekday[1]="Tuesday";
weekday[2]="Wednesday";
weekday[3]="Thursday";
weekday[4]="Friday";
weekday[5]="Saturday";
weekday[6]="Sunday";
$("#datetime").html(namemonth[month]+ " "+weekday[day]+ ", " + hour +":"+ minute);
});