calendar

Contains settings for underlying calendar widget.

<input id="picker" ></input>

<script type="text/javascript">
    $(function () {
        $("#picker").shieldDateTimePicker({
            calendar: {
                dateTooltipTemplate: function(item) {
                        return "" + item.day + "";
                }
            }
        });
    });
</script>

More about all available calendar options, methods and events you can find into the following calendar's API documentation article