diff --git a/navalplanner-webapp/src/main/java/org/navalplanner/web/calendars/BaseCalendarEditionController.java b/navalplanner-webapp/src/main/java/org/navalplanner/web/calendars/BaseCalendarEditionController.java
index f7bfb6465..fdb92f5c0 100644
--- a/navalplanner-webapp/src/main/java/org/navalplanner/web/calendars/BaseCalendarEditionController.java
+++ b/navalplanner-webapp/src/main/java/org/navalplanner/web/calendars/BaseCalendarEditionController.java
@@ -50,7 +50,9 @@ import org.navalplanner.business.workingday.EffortDuration.Granularity;
 import org.navalplanner.web.common.IMessagesForUser;
 import org.navalplanner.web.common.Level;
 import org.navalplanner.web.common.Util;
+import org.navalplanner.web.common.Util.Getter;
 import org.navalplanner.web.common.Util.ICreation;
+import org.navalplanner.web.common.Util.Setter;
 import org.navalplanner.web.common.components.CalendarHighlightedDays;
 import org.navalplanner.web.common.components.CapacityPicker;
 import org.navalplanner.web.common.components.EffortDurationPicker;
@@ -68,6 +70,7 @@ import org.zkoss.zul.Checkbox;
 import org.zkoss.zul.Combobox;
 import org.zkoss.zul.Comboitem;
 import org.zkoss.zul.Datebox;
+import org.zkoss.zul.Hbox;
 import org.zkoss.zul.Label;
 import org.zkoss.zul.Listbox;
 import org.zkoss.zul.Listcell;
@@ -186,15 +189,19 @@ public abstract class BaseCalendarEditionController extends
 
             @Override
             public Checkbox createAt(Component parent) {
-                Checkbox infinitelyOverAssignable = new Checkbox();
-                infinitelyOverAssignable
-                        .setLabel(_("Infinitely Over Assignable"));
-                parent.appendChild(infinitelyOverAssignable);
-                return infinitelyOverAssignable;
+                Checkbox result = createInfinitelyOverAssignableCheckbox();
+                parent.appendChild(result);
+                return result;
             }
         });
     }
 
+    private Checkbox createInfinitelyOverAssignableCheckbox() {
+        Checkbox infinitelyOverAssignable = new Checkbox();
+        infinitelyOverAssignable.setLabel(_("Infinitely Over Assignable"));
+        return infinitelyOverAssignable;
+    }
+
     private void updateWithCapacityFrom(CalendarExceptionType exceptionType) {
         capacityPicker.setValue(exceptionType != null ? exceptionType
                 .getCapacity() : Capacity.create(EffortDuration.zero()));
@@ -331,30 +338,33 @@ public abstract class BaseCalendarEditionController extends
         public void render(Listitem item, Object data) throws Exception {
             final Days day = (Days) data;
 
-            Listcell labelListcell = new Listcell();
-            labelListcell.appendChild(new Label(day.toString()));
-            item.appendChild(labelListcell);
+            addLabelCell(item, day);
 
-            Listcell durationCell = new Listcell();
-            EffortDurationPicker durationPicker = new EffortDurationPicker();
-            durationCell.appendChild(durationPicker);
-            durationPicker.bind(new Util.Getter<EffortDuration>() {
+            EffortDurationPicker normalDurationPicker = new EffortDurationPicker();
+            EffortDurationPicker extraDurationPicker = new EffortDurationPicker();
+            Checkbox checkbox = createInfinitelyOverAssignableCheckbox();
 
-                @Override
-                public EffortDuration get() {
-                    return baseCalendarModel.getDurationAt(day);
-                }
-            }, new Util.Setter<EffortDuration>() {
+            addNormalDurationCell(item, normalDurationPicker);
+            addExtraEffortCell(item, extraDurationPicker, checkbox);
 
-                @Override
-                public void set(EffortDuration value) {
-                    baseCalendarModel.setDurationAt(day, value);
-                    reloadDayInformation();
-                }
-            });
-            durationPicker.setDisabled(baseCalendarModel.isDerived()
+            CapacityPicker capacityPicker = CapacityPicker.workWith(checkbox,
+                    normalDurationPicker,
+                    extraDurationPicker, new Getter<Capacity>() {
+
+                        @Override
+                        public Capacity get() {
+                            return baseCalendarModel.getCapacityAt(day);
+                        }
+                    }, new Setter<Capacity>() {
+
+                        @Override
+                        public void set(Capacity value) {
+                            baseCalendarModel.setCapacityAt(day, value);
+                            reloadDayInformation();
+                        }
+                    });
+            capacityPicker.setDisabled(baseCalendarModel.isDerived()
                     && baseCalendarModel.isDefault(day));
-            item.appendChild(durationCell);
 
             if (baseCalendarModel.isDerived()) {
                 Listcell defaultListcell = new Listcell();
@@ -391,6 +401,29 @@ public abstract class BaseCalendarEditionController extends
             }
         }
 
+        private void addLabelCell(Listitem item, final Days day) {
+            Listcell labelListcell = new Listcell();
+            labelListcell.appendChild(new Label(day.toString()));
+            item.appendChild(labelListcell);
+        }
+
+        private void addNormalDurationCell(Listitem item,
+                EffortDurationPicker normalDurationPicker) {
+            Listcell normalEffortCell = new Listcell();
+            normalEffortCell.appendChild(normalDurationPicker);
+            item.appendChild(normalEffortCell);
+        }
+
+        private void addExtraEffortCell(Listitem item,
+                EffortDurationPicker extraDurationPicker, Checkbox checkbox) {
+            Listcell extraEffortCell = new Listcell();
+            Hbox hbox = new Hbox();
+            hbox.appendChild(extraDurationPicker);
+            hbox.appendChild(checkbox);
+            extraEffortCell.appendChild(hbox);
+            item.appendChild(extraEffortCell);
+        }
+
     }
 
     private void reloadCurrentWindow() {
@@ -1315,4 +1348,5 @@ public abstract class BaseCalendarEditionController extends
             reloadDayInformation();
         }
     }
+
 }
diff --git a/navalplanner-webapp/src/main/java/org/navalplanner/web/calendars/BaseCalendarModel.java b/navalplanner-webapp/src/main/java/org/navalplanner/web/calendars/BaseCalendarModel.java
index aad3846aa..721e55694 100644
--- a/navalplanner-webapp/src/main/java/org/navalplanner/web/calendars/BaseCalendarModel.java
+++ b/navalplanner-webapp/src/main/java/org/navalplanner/web/calendars/BaseCalendarModel.java
@@ -294,12 +294,12 @@ public class BaseCalendarModel extends IntegrationEntityModel implements
     }
 
     @Override
-    public EffortDuration getDurationAt(Days day) {
+    public Capacity getCapacityAt(Days day) {
         if (getBaseCalendar() == null) {
-            return EffortDuration.zero();
+            return Capacity.zero();
         }
         return getBaseCalendar().getCapacityConsideringCalendarDatasOn(
-                selectedDate, day).getStandardEffort();
+                selectedDate, day);
     }
 
     @Override
@@ -328,11 +328,9 @@ public class BaseCalendarModel extends IntegrationEntityModel implements
     }
 
     @Override
-    public void setDurationAt(Days day, EffortDuration value) {
+    public void setCapacityAt(Days day, Capacity value) {
         if (getBaseCalendar() != null) {
-            getBaseCalendar().setCapacityAt(day,
-                    Capacity.create(value).overAssignableWithoutLimit(true),
-                    selectedDate);
+            getBaseCalendar().setCapacityAt(day, value, selectedDate);
         }
     }
 
diff --git a/navalplanner-webapp/src/main/java/org/navalplanner/web/calendars/IBaseCalendarModel.java b/navalplanner-webapp/src/main/java/org/navalplanner/web/calendars/IBaseCalendarModel.java
index 24821d31e..bd08df4a3 100644
--- a/navalplanner-webapp/src/main/java/org/navalplanner/web/calendars/IBaseCalendarModel.java
+++ b/navalplanner-webapp/src/main/java/org/navalplanner/web/calendars/IBaseCalendarModel.java
@@ -197,9 +197,9 @@ public interface IBaseCalendarModel extends IIntegrationEntityModel {
 
     void cancel();
 
-    EffortDuration getDurationAt(Days day);
+    Capacity getCapacityAt(Days day);
 
-    void setDurationAt(Days day, EffortDuration value);
+    void setCapacityAt(Days day, Capacity capacity);
 
     void generateCalendarCodes();
 
diff --git a/navalplanner-webapp/src/main/java/org/navalplanner/web/common/components/CapacityPicker.java b/navalplanner-webapp/src/main/java/org/navalplanner/web/common/components/CapacityPicker.java
index f09b62825..ef6dbf0db 100644
--- a/navalplanner-webapp/src/main/java/org/navalplanner/web/common/components/CapacityPicker.java
+++ b/navalplanner-webapp/src/main/java/org/navalplanner/web/common/components/CapacityPicker.java
@@ -143,4 +143,12 @@ public class CapacityPicker {
         updateExtraEffortDisability();
     }
 
+    public void setDisabled(boolean disabled) {
+        standardEffortPicker.setDisabled(disabled);
+        updateExtraEffortDisability();
+        extraEffortPicker.setDisabled(extraEffortPicker.isDisabled()
+                || disabled);
+        overAssignableWithoutLimitCheckbox.setDisabled(disabled);
+    }
+
 }
diff --git a/navalplanner-webapp/src/main/java/org/navalplanner/web/common/components/EffortDurationPicker.java b/navalplanner-webapp/src/main/java/org/navalplanner/web/common/components/EffortDurationPicker.java
index d07478a02..4e05ba5f4 100644
--- a/navalplanner-webapp/src/main/java/org/navalplanner/web/common/components/EffortDurationPicker.java
+++ b/navalplanner-webapp/src/main/java/org/navalplanner/web/common/components/EffortDurationPicker.java
@@ -87,6 +87,10 @@ public class EffortDurationPicker extends Hbox {
         seconds.setDisabled(disabled);
     }
 
+    public boolean isDisabled() {
+        return hours.isDisabled();
+    }
+
     public void bind(Getter<EffortDuration> getter) {
         updateUIWithValuesFrom(getter.get());
     }
diff --git a/navalplanner-webapp/src/main/webapp/calendars/_edition.zul b/navalplanner-webapp/src/main/webapp/calendars/_edition.zul
index a24ca80b2..d3d407790 100644
--- a/navalplanner-webapp/src/main/webapp/calendars/_edition.zul
+++ b/navalplanner-webapp/src/main/webapp/calendars/_edition.zul
@@ -178,7 +178,8 @@
                         itemRenderer="@{calendarController.editionController.hoursPerDayRenderer}">
                         <listhead>
                             <listheader label="${i18n:_('Day of week')}" width="80px"/>
-                            <listheader label="${i18n:_('Workable Time')}" width="160px"/>
+                            <listheader label="${i18n:_('Normal Effort')}" width="160px"/>
+                            <listheader label="${i18n:_('Extra Effort')}" width="200px"/>
                             <listheader label="${i18n:_('Inh.')}" width="30px" tooltiptext="${i18n:_('Inherited from parent calendar')}" />
                         </listhead>
                     </listbox>