diff --git a/org.adempiere.server/src/main/servlet/org/compiere/web/AdempiereMonitor.java b/org.adempiere.server/src/main/servlet/org/compiere/web/AdempiereMonitor.java
index 3c3cc1a2bd..0e304a1e21 100644
--- a/org.adempiere.server/src/main/servlet/org/compiere/web/AdempiereMonitor.java
+++ b/org.adempiere.server/src/main/servlet/org/compiere/web/AdempiereMonitor.java
@@ -926,10 +926,16 @@ public class AdempiereMonitor extends HttpServlet
 			return "";
 		DateTimeFormatter formatter = DateTimeFormatter.ISO_ZONED_DATE_TIME;
 		MClientInfo clientInfo = MClientInfo.get(AD_Client_ID);
-		if (!Util.isEmpty(clientInfo.getTimeZone()))
-			formatter = formatter.withZone(ZoneId.of(clientInfo.getTimeZone()));
-		else
+		if (!Util.isEmpty(clientInfo.getTimeZone())) {
+			try {
+				formatter = formatter.withZone(ZoneId.of(clientInfo.getTimeZone()));
+			} catch (Exception e) {
+				//fallback to default
+				formatter = formatter.withZone(ZoneId.systemDefault());
+			}
+		} else {
 			formatter = formatter.withZone(ZoneId.systemDefault());
+		}
 		return formatter.format(date.toInstant().truncatedTo(ChronoUnit.SECONDS));
 	}
 
diff --git a/org.idempiere.test/src/org/idempiere/test/model/MSchedulerTest.java b/org.idempiere.test/src/org/idempiere/test/model/MSchedulerTest.java
index fc427196a0..3708d9945d 100644
--- a/org.idempiere.test/src/org/idempiere/test/model/MSchedulerTest.java
+++ b/org.idempiere.test/src/org/idempiere/test/model/MSchedulerTest.java
@@ -94,7 +94,7 @@ public class MSchedulerTest extends AbstractTestCase {
 			cal2.setTimeZone(tz2);
 			cal2.setTimeInMillis(System.currentTimeMillis());
 			hour = cal2.get(Calendar.HOUR_OF_DAY);
-			if (hour > 17) {
+			if (hour >= 17) {
 				cal2.add(Calendar.DAY_OF_MONTH, 1);
 			}
 			cal2.set(Calendar.HOUR_OF_DAY, 17);
@@ -126,7 +126,7 @@ public class MSchedulerTest extends AbstractTestCase {
 			assertFalse(cal2.getTimeInMillis() == ts1.getTime(), "Un-expected date next run");
 			
 			//test with default + 2hour time zone
-			clientInfo.setTimeZone(tz2.getID());
+			clientInfo.setTimeZone(tz2.toZoneId().getId());
 			clientInfo.saveEx();
 			CacheMgt.get().reset();
 			
@@ -143,11 +143,11 @@ public class MSchedulerTest extends AbstractTestCase {
 		} finally {
 			if (schedule != null && schedule.get_ID() > 0)
 				schedule.deleteEx(true);
-			if (!Util.isEmpty(currentTimeZone, true)) {
-				clientInfo.setTimeZone(currentTimeZone);
+			clientInfo.setTimeZone(currentTimeZone);
+			if (clientInfo.is_Changed()) {
 				clientInfo.saveEx();
 				CacheMgt.get().reset();
-			}	
+			}
 		}
 	}
 }