Throw away test dates with year greater than 9999

Author: parkertimmins

x-pack/plugin/logsdb/src/test/java/org/elasticsearch/xpack/logsdb/patternedtext/PatternedTextVsMatchOnlyTextTests.java

@@ -258,8 +258,15 @@ private static String randomSeparator() {
     }
 
     private static String randomTimestamp() {
-        long millis = randomMillisUpToYear9999();
-        ZonedDateTime zonedDateTime = ZonedDateTime.ofInstant(Instant.ofEpochMilli(millis), randomZone());
+        ZonedDateTime zonedDateTime;
+        do {
+            long millis = randomMillisUpToYear9999();
+            zonedDateTime = ZonedDateTime.ofInstant(Instant.ofEpochMilli(millis), randomZone());
+
+        // The random millis are below year 10000 in UTC, but if the date is within 1 day of year 10000, the year can be 10000 in the
+        // selected timezone. Since the date formatter cannot handle years greater than 9999, select another date.
+        } while (zonedDateTime.getYear() == 10000);
+
         DateFormatter formatter = DateFormatter.forPattern(randomDateFormatterPattern()).withLocale(randomLocale(random()));
         return formatter.format(zonedDateTime);
     }