Open member_profile template and search for
replace to
search for
replace to
add after
this
Hope this helps
Addition:
The Time Spent Online time is updated only when the user clicks something in forum.
{$online_status}
replace to
<span id="online_status">{$online_status}</span>
search for
{$timeonline}
replace to
<span id="timeonline">{$timeonline}</span>
add after
</table>
this
<script type="text/javascript">
var interval = 5000;
$(document).ready(function() {
$("#online_status").fadeOut("fast").load(" #online_status").fadeIn("fast");
$("#timeonline").fadeOut("fast").load(" #timeonline").fadeIn("fast");
var refreshId = setInterval(function() {
$("#online_status").fadeOut("fast").load(' #online_status').fadeIn("fast");
$("#timeonline").fadeOut("fast").load(' #timeonline').fadeIn("fast");
}, interval);
$.ajaxSetup({ cache: false });
});
</script>
Hope this helps

Addition:
The Time Spent Online time is updated only when the user clicks something in forum.