diff --git a/navalplanner-business/src/main/java/org/navalplanner/business/planner/entities/ResourceAllocation.java b/navalplanner-business/src/main/java/org/navalplanner/business/planner/entities/ResourceAllocation.java
index fc7ad4ed8..1a9b46676 100644
--- a/navalplanner-business/src/main/java/org/navalplanner/business/planner/entities/ResourceAllocation.java
+++ b/navalplanner-business/src/main/java/org/navalplanner/business/planner/entities/ResourceAllocation.java
@@ -836,6 +836,14 @@ public abstract class ResourceAllocation<T extends DayAssignment> extends
         return Collections.unmodifiableSet(derivedAllocations);
     }
 
+    public LocalDate getStartConsideringAssignments() {
+        List<? extends DayAssignment> assignments = getAssignments();
+        if (assignments.isEmpty()) {
+            return getStartDate();
+        }
+        return assignments.get(0).getDay();
+    }
+
     public LocalDate getStartDate() {
         return LocalDate.fromDateFields(task.getStartDate());
     }
diff --git a/navalplanner-webapp/src/main/java/org/navalplanner/web/planner/allocation/AdvancedAllocationController.java b/navalplanner-webapp/src/main/java/org/navalplanner/web/planner/allocation/AdvancedAllocationController.java
index 147f5a879..fb273dfea 100644
--- a/navalplanner-webapp/src/main/java/org/navalplanner/web/planner/allocation/AdvancedAllocationController.java
+++ b/navalplanner-webapp/src/main/java/org/navalplanner/web/planner/allocation/AdvancedAllocationController.java
@@ -139,12 +139,24 @@ public class AdvancedAllocationController extends GenericForwardComposer {
                 return new Interval(task.getStartDate(), task
                         .getEndDate());
             } else {
-                LocalDate start = all.get(0).getStartDate();
-                LocalDate end = getEnd(all);
+                LocalDate start = min(all.get(0)
+                        .getStartConsideringAssignments(), all.get(0)
+                        .getStartDate());
+                LocalDate taskEndDate = LocalDate.fromDateFields(task
+                        .getEndDate());
+                LocalDate end = max(getEnd(all), taskEndDate);
                 return new Interval(asDate(start), asDate(end));
             }
         }
 
+        private LocalDate min(LocalDate... dates) {
+            return Collections.min(Arrays.asList(dates), null);
+        }
+
+        private LocalDate max(LocalDate... dates) {
+            return Collections.max(Arrays.asList(dates), null);
+        }
+
         private static LocalDate getEnd(List<ResourceAllocation<?>> all) {
             ArrayList<ResourceAllocation<?>> reversed = reverse(all);
             LocalDate end = reversed.get(0).getEndDate();