Index: PersistentAlarm.c
===================================================================
diff -u -rffbcb3688e46a39410a395e796f4249363b96f1c -r7f049fb55e8f7fd41cf2dbd19a0e43d4e684af78
--- PersistentAlarm.c	(.../PersistentAlarm.c)	(revision ffbcb3688e46a39410a395e796f4249363b96f1c)
+++ PersistentAlarm.c	(.../PersistentAlarm.c)	(revision 7f049fb55e8f7fd41cf2dbd19a0e43d4e684af78)
@@ -98,16 +98,24 @@
     {
         if ( isOutOfRange )
         {
-            persistentAlarms[ alarmIndex ].inRangeStartTime = getMSTimerCount();
-            if ( calcTimeSince( persistentAlarms[ alarmIndex ].outOfRangeStartTime ) >= persistentAlarms[ alarmIndex ].persistentTriggerPeriod )
+            persistentAlarms[ alarmIndex ].inRangeStartTime = 0;
+            if ( persistentAlarms[ alarmIndex ].outOfRangeStartTime == 0 )
             {
+                persistentAlarms[ alarmIndex ].outOfRangeStartTime = getMSTimerCount();
+            }
+            if ( didTimeout( persistentAlarms[ alarmIndex ].outOfRangeStartTime, persistentAlarms[ alarmIndex ].persistentTriggerPeriod ) )
+            {
                 SET_ALARM_WITH_1_F32_DATA( persistentAlarms[ alarmIndex ].alarm, data );
             }
         }
         else
         {
-            persistentAlarms[ alarmIndex ].outOfRangeStartTime = getMSTimerCount();
-            BOOL const isInRangePersistent = calcTimeSince( persistentAlarms[ alarmIndex ].inRangeStartTime ) >= persistentAlarms[ alarmIndex ].persistentClearPeriod;
+            persistentAlarms[ alarmIndex ].outOfRangeStartTime = 0;
+            if ( persistentAlarms[ alarmIndex ].inRangeStartTime == 0 )
+            {
+                persistentAlarms[ alarmIndex ].inRangeStartTime = getMSTimerCount();
+            }
+            BOOL const isInRangePersistent = didTimeout( persistentAlarms[ alarmIndex ].inRangeStartTime, persistentAlarms[ alarmIndex ].persistentClearPeriod );
             if ( persistentAlarms[ alarmIndex ].isClearable && isInRangePersistent )
             {
                 clearAlarm( persistentAlarms[ alarmIndex ].alarm );