If you decide to add a boolean to the page type you can use the IfTrue Transformation Method
<%# IfTrue(Eval("EventSchedule"), "", "<a href='mylink'>Schedule</a>") %>
And as Zacahry mentioned you can use IfEmpty similarly
<%# IfEmpty(Eval("EventSchedule"),"","<a href='mylink'>"+Eval("EventSchedule")+"</a>") %>
Or.. I dont know how you are using that field.. if it is your link....
<%# IfEmpty(Eval("EventSchedule"),"","<a href="+Eval("EventSchedule")+">Schedule</a>") %>