Here is my code to have tooltip on fullcalender events http://jsfiddle.net/539jx/3/
eventMouseover: function (data, event, view) {
tooltip = '<div class="tooltiptopicevent" style="width:auto;height:auto;background:#feb811;position:absolute;z-index:10001;padding:10px 10px 10px 10px ; line-height: 200%;">' + 'title: ' + ': ' + data.title + '</br>' + 'start: ' + ': ' + data.start + '</div>';
$("body").append(tooltip);
$(this).mouseover(function (e) {
$(this).css('z-index', 10000);
$('.tooltiptopicevent').fadeIn('500');
$('.tooltiptopicevent').fadeTo('10', 1.9);
}).mousemove(function (e) {
$('.tooltiptopicevent').css('top', e.pageY + 10);
$('.tooltiptopicevent').css('left', e.pageX + 20);
});
},
eventMouseout: function (data, event, view) {
$(this).css('z-index', 8);
$('.tooltiptopicevent').remove();
}