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 ec5c73b12..b2d409b6e 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
@@ -2179,4 +2179,11 @@ public abstract class ResourceAllocation<T extends DayAssignment> extends
                 : null;
     }
 
+    public boolean isManualAssignmentFunction() {
+        if (assignmentFunction != null) {
+            return assignmentFunction.isManual();
+        }
+        return false;
+    }
+
 }
diff --git a/navalplanner-business/src/main/java/org/navalplanner/business/planner/entities/Task.java b/navalplanner-business/src/main/java/org/navalplanner/business/planner/entities/Task.java
index 71bc91f4c..0350c1fb8 100644
--- a/navalplanner-business/src/main/java/org/navalplanner/business/planner/entities/Task.java
+++ b/navalplanner-business/src/main/java/org/navalplanner/business/planner/entities/Task.java
@@ -1021,4 +1021,22 @@ public class Task extends TaskElement implements ITaskPositionConstrained {
         return !calendar.getCapacityOn(PartialDay.wholeDay(day)).isZero();
     }
 
+    public static void convertOnStartInFixedDate(Task task) {
+        TaskPositionConstraint taskConstraint = task.getPositionConstraint();
+        if (taskConstraint.isValid(PositionConstraintType.START_IN_FIXED_DATE,
+                task.getIntraDayStartDate())) {
+            taskConstraint.update(PositionConstraintType.START_IN_FIXED_DATE,
+                    task.getIntraDayStartDate());
+        }
+    }
+
+    public boolean isManualAnyAllocation() {
+        for (ResourceAllocation<?> each : resourceAllocations) {
+            if (each.isManualAssignmentFunction()) {
+                return true;
+            }
+        }
+        return false;
+    }
+
 }
diff --git a/navalplanner-webapp/src/main/java/org/navalplanner/web/planner/order/SubcontractModel.java b/navalplanner-webapp/src/main/java/org/navalplanner/web/planner/order/SubcontractModel.java
index 7a128239f..0b27a677b 100644
--- a/navalplanner-webapp/src/main/java/org/navalplanner/web/planner/order/SubcontractModel.java
+++ b/navalplanner-webapp/src/main/java/org/navalplanner/web/planner/order/SubcontractModel.java
@@ -28,10 +28,8 @@ import org.navalplanner.business.common.exceptions.ValidationException;
 import org.navalplanner.business.externalcompanies.daos.IExternalCompanyDAO;
 import org.navalplanner.business.externalcompanies.entities.ExternalCompany;
 import org.navalplanner.business.planner.daos.ISubcontractedTaskDataDAO;
-import org.navalplanner.business.planner.entities.PositionConstraintType;
 import org.navalplanner.business.planner.entities.SubcontractedTaskData;
 import org.navalplanner.business.planner.entities.Task;
-import org.navalplanner.business.planner.entities.TaskPositionConstraint;
 import org.springframework.beans.factory.annotation.Autowired;
 import org.springframework.beans.factory.config.BeanDefinition;
 import org.springframework.context.annotation.Scope;
@@ -109,22 +107,13 @@ public class SubcontractModel implements ISubcontractModel {
                 }
 
                 task.removeAllSatisfiedResourceAllocations();
-                convertOnStartOnFixedDate(task);
+                Task.convertOnStartInFixedDate(task);
             }
 
             recalculateTaskLength();
         }
     }
 
-    private void convertOnStartOnFixedDate(Task task) {
-        TaskPositionConstraint taskConstraint = task.getPositionConstraint();
-        if (taskConstraint.isValid(PositionConstraintType.START_IN_FIXED_DATE,
-                task.getIntraDayStartDate())) {
-            taskConstraint.update(PositionConstraintType.START_IN_FIXED_DATE,
-                    task.getIntraDayStartDate());
-        }
-    }
-
     private void recalculateTaskLength() {
         GanttDate previousStartDate = ganttTask.getBeginDate();
         GanttDate previousEnd = ganttTask.getEndDate();
diff --git a/navalplanner-webapp/src/main/java/org/navalplanner/web/planner/tabs/AdvancedAllocationTabCreator.java b/navalplanner-webapp/src/main/java/org/navalplanner/web/planner/tabs/AdvancedAllocationTabCreator.java
index 1fd62b34a..0985e5517 100644
--- a/navalplanner-webapp/src/main/java/org/navalplanner/web/planner/tabs/AdvancedAllocationTabCreator.java
+++ b/navalplanner-webapp/src/main/java/org/navalplanner/web/planner/tabs/AdvancedAllocationTabCreator.java
@@ -136,6 +136,9 @@ public class AdvancedAllocationTabCreator {
             Validate
                     .isTrue(allocationResult.getAggregate() == modifiedAllocations);
             allocationResult.applyTo(planningState.getCurrentScenario(), task);
+            if (task.isManualAnyAllocation()) {
+                Task.convertOnStartInFixedDate(task);
+            }
             updateParentsPositions(task);
         }
 
diff --git a/navalplanner-webapp/src/main/java/org/navalplanner/web/planner/taskedition/AdvancedAllocationTaskController.java b/navalplanner-webapp/src/main/java/org/navalplanner/web/planner/taskedition/AdvancedAllocationTaskController.java
index 157a7a475..c202452fb 100644
--- a/navalplanner-webapp/src/main/java/org/navalplanner/web/planner/taskedition/AdvancedAllocationTaskController.java
+++ b/navalplanner-webapp/src/main/java/org/navalplanner/web/planner/taskedition/AdvancedAllocationTaskController.java
@@ -143,6 +143,9 @@ public class AdvancedAllocationTaskController extends GenericForwardComposer {
         @Override
         public void accepted(AggregateOfResourceAllocations aggregate) {
             allocation.applyTo(planningState.getCurrentScenario(), task);
+            if (task.isManualAnyAllocation()) {
+                Task.convertOnStartInFixedDate(task);
+            }
             askForReloads();
         }