Dates with missing UTC offset should be interpreted (in nashorn-compat mode) as UTC time when they are "strict" only.

iamstolis · iamstolis · commit 35d5ca139213 · 2025-05-23T10:50:07.000+02:00
diff --git a/graal-js/src/com.oracle.truffle.js.parser/src/com/oracle/truffle/js/parser/date/DateParser.java b/graal-js/src/com.oracle.truffle.js.parser/src/com/oracle/truffle/js/parser/date/DateParser.java
@@ -750,7 +750,8 @@ private boolean patchResult(final boolean strict) {
     }
 
     private boolean isUTCDefaultTimezone(boolean dateOnly, boolean strict) {
-        return (strict || realm.getContext().getLanguageOptions().useUTCForLegacyDates()) && dateOnly;
+        return realm.getContext().isOptionNashornCompatibilityMode() ? strict :
+                (dateOnly && (strict || realm.getContext().getLanguageOptions().useUTCForLegacyDates()));
     }
 
     private static void addName(final String str, final int type, final int value) {

Original file line number	Diff line number	Diff line change
`@@ -750,7 +750,8 @@ private boolean patchResult(final boolean strict) {`
`750`	`750`	`}`
`751`	`751`
`752`	`752`	`private boolean isUTCDefaultTimezone(boolean dateOnly, boolean strict) {`
`753`		`- return (strict \|\| realm.getContext().getLanguageOptions().useUTCForLegacyDates()) && dateOnly;`
	`753`	`+ return realm.getContext().isOptionNashornCompatibilityMode() ? strict :`
	`754`	`+ (dateOnly && (strict \|\| realm.getContext().getLanguageOptions().useUTCForLegacyDates()));`
`754`	`755`	`}`
`755`	`756`
`756`	`757`	`private static void addName(final String str, final int type, final int value) {`