skip test week with time type in Jan and Dec

Signed-off-by: Lantao Jin <[email protected]>

core/src/test/java/org/opensearch/sql/expression/datetime/ExtractTest.java

@@ -5,7 +5,7 @@
 
 package org.opensearch.sql.expression.datetime;
 
-import static java.time.temporal.ChronoField.DAY_OF_WEEK;
+import static java.time.temporal.ChronoField.ALIGNED_WEEK_OF_YEAR;
 import static org.junit.jupiter.api.Assertions.assertEquals;
 import static org.opensearch.sql.data.type.ExprCoreType.LONG;
 
@@ -92,19 +92,23 @@ private void datePartWithTimeArgQuery(String part, String time, long expected) {
 
   @Test
   public void testExtractDatePartWithTimeType() {
-    datePartWithTimeArgQuery(
-        "DAY", timeInput, LocalDate.now(functionProperties.getQueryStartClock()).getDayOfMonth());
+    LocalDate now = LocalDate.now(functionProperties.getQueryStartClock());
 
-    datePartWithTimeArgQuery(
-        "WEEK",
-        timeInput,
-        LocalDate.now(functionProperties.getQueryStartClock()).get(DAY_OF_WEEK));
+    datePartWithTimeArgQuery("DAY", timeInput, now.getDayOfMonth());
 
-    datePartWithTimeArgQuery(
-        "MONTH", timeInput, LocalDate.now(functionProperties.getQueryStartClock()).getMonthValue());
+    // To avoid flaky test, skip the testing in December and January because the WEEK is ISO 8601
+    // week-of-week-based-year which is considered to start on a Monday and week 1 is the first week
+    // with >3 days. it is possible for early-January dates to be part of the 52nd or 53rd week of
+    // the previous year, and for late-December dates to be part of the first week of the next year.
+    // For example, 2005-01-02 is part of the 53rd week of year 2004, while 2012-12-31 is part of
+    // the first week of 2013
+    if (now.getMonthValue() != 1 && now.getMonthValue() != 12) {
+      datePartWithTimeArgQuery("WEEK", datetimeInput, now.get(ALIGNED_WEEK_OF_YEAR));
+    }
 
-    datePartWithTimeArgQuery(
-        "YEAR", timeInput, LocalDate.now(functionProperties.getQueryStartClock()).getYear());
+    datePartWithTimeArgQuery("MONTH", timeInput, now.getMonthValue());
+
+    datePartWithTimeArgQuery("YEAR", timeInput, now.getYear());
   }
 
   @ParameterizedTest(name = "{0}")