Index: ssts-tousse/src/main/java/com/forgon/disinfectsystem/tousse/instrumentinstance/service/InstrumentInstanceManagerImpl.java
===================================================================
diff -u -r34708 -r34711
--- ssts-tousse/src/main/java/com/forgon/disinfectsystem/tousse/instrumentinstance/service/InstrumentInstanceManagerImpl.java	(.../InstrumentInstanceManagerImpl.java)	(revision 34708)
+++ ssts-tousse/src/main/java/com/forgon/disinfectsystem/tousse/instrumentinstance/service/InstrumentInstanceManagerImpl.java	(.../InstrumentInstanceManagerImpl.java)	(revision 34711)
@@ -1444,11 +1444,15 @@
 	 */
 	private long getInstrumentInstanceUseDay(
 			InstrumentInstance instrumentInstance) {
-		if(instrumentInstance == null || instrumentInstance.getProductionDate() == null){
+		if(instrumentInstance == null || !DatabaseUtil.isPoIdValid(instrumentInstance.getMaterialEntryId())){
 			return 0;
 		}
-		Date productionDate = instrumentInstance.getProductionDate();
-		long l = new Date().getTime() - productionDate.getTime();
+		MaterialEntry materialEntry = (MaterialEntry) objectDao.getById(MaterialEntry.class.getSimpleName(), instrumentInstance.getMaterialEntryId());
+		if(materialEntry == null || materialEntry.getTime() == null){
+			return 0;
+		}
+		Date materialEntryTime = materialEntry.getTime();
+		long l = new Date().getTime() - materialEntryTime.getTime();
 		long d = l / (24 * 60 * 60 * 1000);
 		return d;
 	}