****************************************INFORMATION
<xf:foreach loop="$users" value="$user">
<xf:set var="$rightIcon"> <<<< This is a setings parameter. Turn ON or Turn OFF display clock icon, maybe.
<span title="{{ phrase('joined:') }} {{ date($user.register_date, 'Y-M-d') }}" data-xf-init="tooltip"> <<<< You will need this, this will write down the data you want.
<xf:fa icon="far fa-clock" /> <<<< This is the watch icon.
</span>
</xf:set>
************************************************************************
So:
FIND >>
<xf:set var="$rightIcon">
<span title="{{ phrase('joined:') }} {{ date($user.register_date, 'l') }}" data-xf-init="tooltip">
<xf:fa icon="far fa-clock" />
</span>
</xf:set>
>> AND DELETE
*The text written with red can be different than you.