Found the answer – this is not an issue with joomlart’s template but with the component I am using – Sobi2… anyone else with issue here is the solution.
This is due a CSS problem with your template. Please edit this file: Edit file: components/com_sobi2/includes/js/jscalendar/calendar-system.css.
And add this definition in the .calendar style last line :z-index:9999;
.calendar {
position: relative;
display: none;
border: 1px solid;
border-color: #fff #000 #000 #fff;
font-size: 11px;
cursor: default;
background: Window;
color: WindowText;
font-family: tahoma,verdana,sans-serif;
z-index:9999;
}