diff --git a/workers.py b/workers.py
index 5a340a0..528f342 100644
--- a/workers.py
+++ b/workers.py
@@ -50,6 +50,9 @@ class Worker:
             else:
                 days_to_work = (self.end_date - Rota.start_date).days
 
+                if days_to_work < 0:
+                    days_to_work = 0
+
                 # add unavalabilities
                 for weeks_days in Rota.weeks_days_product[days_to_work:]:
                     week, day = weeks_days
@@ -62,21 +65,25 @@ class Worker:
             end_oop_date = datetime.datetime.strptime(end_oop,
                                                       "%Y/%m/%d").date()
 
-            if end_oop_date > Rota.rota_end_date:
-                end_oop_date = Rota.rota_end_date
+            
+            # ignore oops if they finish before the rota start date
+            if end_oop_date < Rota.start_date:
+                if end_oop_date > Rota.rota_end_date:
+                    end_oop_date = Rota.rota_end_date
 
-            if start_oop_date < Rota.start_date:
-                start_oop_date = Rota.start_date
+                if start_oop_date < Rota.start_date:
+                    start_oop_date = Rota.start_date
 
-            oop_length = (end_oop_date - start_oop_date).days
-            days_to_work = days_to_work - oop_length
 
-            days_until_oop = (start_oop_date - Rota.start_date).days
+                oop_length = (end_oop_date - start_oop_date).days
+                days_to_work = days_to_work - oop_length
 
-            for weeks_days in Rota.weeks_days_product[
-                    days_until_oop:days_until_oop + oop_length]:
-                week, day = weeks_days
-                Rota.unavailable_to_work.add((self.id, week, day))
+                days_until_oop = (start_oop_date - Rota.start_date).days
+
+                for weeks_days in Rota.weeks_days_product[
+                        days_until_oop:days_until_oop + oop_length]:
+                    week, day = weeks_days
+                    Rota.unavailable_to_work.add((self.id, week, day))
 
         if pref_not_to_work is not None:
             # loop throught dates converting to week / day combination