update

velox/docs/functions/spark/datetime.rst

@@ -138,10 +138,8 @@ These functions support TIMESTAMP and DATE input types.
     Create timestamp from ``year``, ``month``, ``day``, ``hour``, ``min`` and ``sec`` fields.
     If the ``timezone`` parameter is provided,
     the function interprets the input time components as being in the specified ``timezone``.
-    Otherwise if ``session_timezone`` is configured,
-    the function assumes the inputs are in the session's configured time zone.
-    If neither the ``timezone`` parameter nor the ``session_timezone`` configuration is specified,
-    an exception will be thrown.
+    Otherwise the function assumes the inputs are in the session's configured time zone.
+    Requires ``session_timezone`` to be set, or an exceptions will be thrown.
 
     Returns the timestamp adjusted to the GMT time zone. ::
 

velox/functions/sparksql/DateTimeFunctions.cpp

@@ -125,8 +125,7 @@ class MakeTimestampFunction : public exec::VectorFunction {
         });
       }
     } else {
-      // Otherwise use session timezone. If session timezone is not specified,
-      // use default value 0(UTC timezone).
+      // Otherwise use session timezone.
       rows.applyToSelected([&](vector_size_t row) {
         auto timestamp = makeTimeStampFromDecodedArgs(
             row, year, month, day, hour, minute, micros);