1 files changed, 7 insertions, 2 deletions
diff --git a/deps/v8/src/dateparser-inl.h b/deps/v8/src/dateparser-inl.h
index 47a7c6e7ff..fd4bed2df6 100644
--- a/deps/v8/src/dateparser-inl.h
+++ b/deps/v8/src/dateparser-inl.h
@@ -343,8 +343,13 @@ DateParser::DateToken DateParser::ParseES5DateTime(
     }
     if (!scanner->Peek().IsEndOfInput()) return DateToken::Invalid();
   }
-  // Successfully parsed ES5 Date Time String. Default to UTC if no TZ given.
-  if (tz->IsEmpty()) tz->Set(0);
+  // Successfully parsed ES5 Date Time String.
+  // ES#sec-date-time-string-format Date Time String Format
+  // "When the time zone offset is absent, date-only forms are interpreted
+  //  as a UTC time and date-time forms are interpreted as a local time."
+  if (tz->IsEmpty() && time->IsEmpty()) {
+    tz->Set(0);
+  }
   day->set_iso_date();
   return DateToken::EndOfInput();
 }