diff --git a/src/main/java/org/jlab/dtm/business/session/EventFacade.java b/src/main/java/org/jlab/dtm/business/session/EventFacade.java
index 0f32e28..349b04a 100644
--- a/src/main/java/org/jlab/dtm/business/session/EventFacade.java
+++ b/src/main/java/org/jlab/dtm/business/session/EventFacade.java
@@ -194,6 +194,28 @@ public void editEvent(BigInteger eventId, Date timeUp, String title, BigInteger
       throw new InternalException("EventType with ID " + eventTypeId + " not found");
     }
 
+    List<Event> eventList =
+        this.findEventListWithIncidents(
+            event.getTimeDown(), timeUp == null ? new Date() : timeUp, type.getEventTypeId());
+
+    List<Event> differentEventList = new ArrayList<>();
+
+    for (Event e : eventList) {
+      if (!e.getEventId().equals(event.getEventId())) {
+        differentEventList.add(e);
+      }
+    }
+
+    if (!differentEventList.isEmpty()) {
+      throw new UserFriendlyException(
+          "Event modification results in event of type "
+              + type.getAbbreviation()
+              + " time period collision with existing event "
+              + eventList.get(0).getEventId()
+              + " named: "
+              + eventList.get(0).getTitle());
+    }
+
     event.setTitle(title);
     event.setEventType(type);
 
diff --git a/src/main/java/org/jlab/dtm/business/session/IncidentFacade.java b/src/main/java/org/jlab/dtm/business/session/IncidentFacade.java
index 60b377c..6cb7c64 100644
--- a/src/main/java/org/jlab/dtm/business/session/IncidentFacade.java
+++ b/src/main/java/org/jlab/dtm/business/session/IncidentFacade.java
@@ -408,7 +408,8 @@ public Event addEvent(
       throw new UserFriendlyException(
           "An event of type "
               + type.getName()
-              + " is already open (cannot add another open event of same type)");
+              + " is already open (cannot add another open event of same type).  The existing event name: "
+              + event.getTitle());
     }
 
     /* we must ensure that an incident has a timeUp if the event is closed*/
@@ -420,6 +421,20 @@ public Event addEvent(
       throw new UserFriendlyException("Incident time up can not come after event time up");
     }
 
+    List<Event> eventList =
+        eventFacade.findEventListWithIncidents(
+            timeDown, eventTimeUp == null ? new Date() : eventTimeUp, type.getEventTypeId());
+
+    if (!eventList.isEmpty()) {
+      throw new UserFriendlyException(
+          "Event addition results in type "
+              + type.getAbbreviation()
+              + " time period collision with existing event "
+              + eventList.get(0).getEventId()
+              + " named: "
+              + eventList.get(0).getTitle());
+    }
+
     // Enforce restrictions on closed events.  Operators must work with open events if they wish to
     // mettle in the past
     AuditContext auditCtx = AuditContext.getCurrentInstance();
@@ -538,6 +553,30 @@ public void editIncident(
 
     boolean wasPreviouslyClosed = incident.getTimeUp() != null;
 
+    List<Event> eventList =
+        eventFacade.findEventListWithIncidents(
+            timeDown.before(event.getTimeDown()) ? timeDown : event.getTimeDown(),
+            event.getTimeUp() == null ? new Date() : event.getTimeUp(),
+            event.getEventType().getEventTypeId());
+
+    List<Event> differentEventList = new ArrayList<>();
+
+    for (Event e : eventList) {
+      if (!e.getEventId().equals(event.getEventId())) {
+        differentEventList.add(e);
+      }
+    }
+
+    if (!differentEventList.isEmpty()) {
+      throw new UserFriendlyException(
+          "Incident modification results in event type "
+              + event.getEventType().getAbbreviation()
+              + " time period collision with existing event "
+              + eventList.get(0).getEventId()
+              + " named: "
+              + eventList.get(0).getTitle());
+    }
+
     validateAndPopulateIncident(
         incident,
         title,
@@ -640,6 +679,30 @@ public void addIncident(
 
     event.setTitle(eventTitle);
 
+    List<Event> eventList =
+        eventFacade.findEventListWithIncidents(
+            timeDown.before(event.getTimeDown()) ? timeDown : event.getTimeDown(),
+            event.getTimeUp() == null ? new Date() : event.getTimeUp(),
+            event.getEventType().getEventTypeId());
+
+    List<Event> differentEventList = new ArrayList<>();
+
+    for (Event e : eventList) {
+      if (!e.getEventId().equals(event.getEventId())) {
+        differentEventList.add(e);
+      }
+    }
+
+    if (!differentEventList.isEmpty()) {
+      throw new UserFriendlyException(
+          "Incident modification results in event type "
+              + event.getEventType().getAbbreviation()
+              + " time period collision with existing event "
+              + eventList.get(0).getEventId()
+              + " named: "
+              + eventList.get(0).getTitle());
+    }
+
     em.flush();
 
     Incident incident = new Incident();