diff --git a/navalplanner-business/src/main/java/org/navalplanner/business/calendars/entities/AvailabilityTimeLine.java b/navalplanner-business/src/main/java/org/navalplanner/business/calendars/entities/AvailabilityTimeLine.java
index ad3d88f86..51f52253f 100644
--- a/navalplanner-business/src/main/java/org/navalplanner/business/calendars/entities/AvailabilityTimeLine.java
+++ b/navalplanner-business/src/main/java/org/navalplanner/business/calendars/entities/AvailabilityTimeLine.java
@@ -222,6 +222,10 @@ public class AvailabilityTimeLine {
                     end));
         }
 
+        static Interval all() {
+            return new Interval(StartOfTime.create(), EndOfTime.create());
+        }
+
         static Interval from(LocalDate date) {
             return new Interval(new FixedPoint(date), EndOfTime.create());
         }
@@ -281,7 +285,6 @@ public class AvailabilityTimeLine {
         private DatePoint max(DatePoint... values) {
             return (DatePoint) Collections.max(Arrays.asList(values));
         }
-
     }
 
     public static AvailabilityTimeLine allValid() {
@@ -313,6 +316,10 @@ public class AvailabilityTimeLine {
         }
     }
 
+    public void allInvalid() {
+        insert(Interval.all());
+    }
+
     public void invalidAt(LocalDate date) {
         Interval point = Interval.point(date);
         insert(point);
diff --git a/navalplanner-business/src/test/java/org/navalplanner/business/test/calendars/entities/AvailabilityTimeLineTest.java b/navalplanner-business/src/test/java/org/navalplanner/business/test/calendars/entities/AvailabilityTimeLineTest.java
index 084428440..59ea6e1d3 100644
--- a/navalplanner-business/src/test/java/org/navalplanner/business/test/calendars/entities/AvailabilityTimeLineTest.java
+++ b/navalplanner-business/src/test/java/org/navalplanner/business/test/calendars/entities/AvailabilityTimeLineTest.java
@@ -160,6 +160,25 @@ public class AvailabilityTimeLineTest {
         assertTrue(timeLine.isValid(contemporaryExample.minusDays(1)));
     }
 
+    @Test
+    public void addingAllInvalidMakesAllInvalid() {
+        AvailabilityTimeLine timeLine = AvailabilityTimeLine.allValid();
+        timeLine.invalidFrom(contemporaryExample);
+        timeLine.invalidUntil(contemporaryExample.minusDays(10));
+
+        assertFalse(timeLine.isValid(earlyExample));
+        assertTrue(timeLine.isValid(contemporaryExample.minusDays(10)));
+
+        assertFalse(timeLine.isValid(contemporaryExample));
+        assertFalse(timeLine.isValid(lateExample));
+
+        timeLine.allInvalid();
+        assertFalse(timeLine.isValid(earlyExample));
+        assertFalse(timeLine.isValid(contemporaryExample.minusDays(10)));
+        assertFalse(timeLine.isValid(contemporaryExample));
+        assertFalse(timeLine.isValid(lateExample));
+    }
+
     @Test
     public void addingSeveralTypesOfIntervals() {
         AvailabilityTimeLine timeLine = AvailabilityTimeLine.allValid();
@@ -202,5 +221,4 @@ public class AvailabilityTimeLineTest {
             current = current.plusDays(1);
         }
     }
-
 }