Constructor changed.

src/agenda/ActTime.java

@@ -18,7 +18,8 @@ public class ActTime {
     }
     
     public ActTime(String beginTime, String endTime){
-
+        this.beginTime = new GregorianCalendar();
+        this.endTime = new GregorianCalendar();
     }
 
     public void setBeginTime(int y, int m, int d, int hh, int mm){