Getting error in LINQ

LINQ to Entities does not recognize the method 'System.DateTime ToDateTime(System.String)' method, and this method cannot be translated into a store expression.

 

IN This Line :-

 

Events = db.Events.Where(a => (a.Active == true) && (a.IsDelete == false && a.IsRejected == false && Convert.ToDateTime(a.EventEndDate) > DateTime.Now)).ToList();