diff --git a/x-pack/plugin/core/src/test/java/org/elasticsearch/xpack/core/ml/calendars/ScheduledEventTests.java b/x-pack/plugin/core/src/test/java/org/elasticsearch/xpack/core/ml/calendars/ScheduledEventTests.java
index 05209628542fe..6508ee5cb2054 100644
--- a/x-pack/plugin/core/src/test/java/org/elasticsearch/xpack/core/ml/calendars/ScheduledEventTests.java
+++ b/x-pack/plugin/core/src/test/java/org/elasticsearch/xpack/core/ml/calendars/ScheduledEventTests.java
@@ -18,6 +18,7 @@
 
 import java.io.IOException;
 import java.time.Clock;
+import java.time.Instant;
 import java.time.ZoneOffset;
 import java.time.ZonedDateTime;
 import java.util.EnumSet;
@@ -28,7 +29,7 @@
 public class ScheduledEventTests extends AbstractSerializingTestCase<ScheduledEvent> {
 
     public static ScheduledEvent createScheduledEvent(String calendarId) {
-        ZonedDateTime start = Clock.systemUTC().instant().atZone(ZoneOffset.UTC);
+        ZonedDateTime start = nowWithMillisResolution();
         return new ScheduledEvent(randomAlphaOfLength(10), start, start.plusSeconds(randomIntBetween(1, 10000)),
                 calendarId, null);
     }
@@ -119,4 +120,8 @@ public void testLenientParser() throws IOException {
             ScheduledEvent.LENIENT_PARSER.apply(parser, null);
         }
     }
+
+    private static ZonedDateTime nowWithMillisResolution() {
+        return Instant.ofEpochMilli(Clock.systemUTC().millis()).atZone(ZoneOffset.UTC);
+    }
 }