$('ui_tpicker_time_fromDateTableFilter') – DOM element (like DIV):
$('.ui_tpicker_time_fromDateTableFilter') – it is class – DOT means class
$('#ui_tpicker_time_fromDateTableFilter') – hash means ID - it is ID like:
<dd class="ui_tpicker_time" id="ui_tpicker_time_fromDateTableFilter">10:02</dd>