ADDITIONAL SYSTEM INFORMATION :
Windows 11 Enterprise 23H2 22631.5189 x64

Java 17.0.13, Oracle openjdk 21.0.7 , Oracle openjdk 24.0.1

A DESCRIPTION OF THE PROBLEM :
while running

import java.text.*;
import java.util.*;
public class Main {
    public static void main(String args[]) throws ParseException {
        DateFormat date = DateFormat.getDateTimeInstance(2, 2, Locale.US);
        String s = "Apr 23, 2025, 8:00:59 PM";

        // Print the actual pattern being used
        if (date instanceof SimpleDateFormat) {
            System.out.println("Format pattern: " + ((SimpleDateFormat)date).toPattern());
        }

        try {
            Date parsedDate = date.parse(s);
            System.out.println("Parsed date: " + parsedDate);
        } catch (ParseException e) {
            System.out.println("Parse exception: " + e.getMessage());
        }
    }
}



Result for Oracle openjdk 21.0.7 :
Format pattern: MMM d, y, h:mm:ss a
Parse exception: Unparseable date: "Apr 23, 2025, 8:00:59 PM"

but when running with Java 17.0.13 or Oracle 24.0.1
we are able to parse date using same code

Result for java 17.0.13 :
Format pattern: MMM d, y, h:mm:ss a
Parsed date: Wed Apr 23 20:00:59 IST 2025

Result for Oracle openjdk 24.0.1 :
Format pattern: MMM d, y, h:mm:ss a
Parsed date: Wed Apr 23 20:00:59 IST 2025

REGRESSION : Last worked in version 17

STEPS TO FOLLOW TO REPRODUCE THE PROBLEM :
Run main function of Main class code given in description in with Oracle openjdk 21.0.7 getting Parse exception: Unparseable date: "Apr 23, 2025, 8:00:59 PM"

and run same code with Oracle openjdk 24.0.1 or Java 17.0.13
able to parse date


EXPECTED VERSUS ACTUAL BEHAVIOR :
EXPECTED -
Format pattern: MMM d, y, h:mm:ss a
Parsed date: Wed Apr 23 20:00:59 IST 2025
ACTUAL -
Format pattern: MMM d, y, h:mm:ss a
Parse exception: Unparseable date: "Apr 23, 2025, 8:00:59 PM"

---------- BEGIN SOURCE ----------
import java.text.*;
import java.util.*;
public class Main {
    public static void main(String args[]) throws ParseException {
        DateFormat date = DateFormat.getDateTimeInstance(2, 2, Locale.US);
        String s = "Apr 23, 2025, 8:00:59 PM";

        // Print the actual pattern being used
        if (date instanceof SimpleDateFormat) {
            System.out.println("Format pattern: " + ((SimpleDateFormat)date).toPattern());
        }

        try {
            Date parsedDate = date.parse(s);
            System.out.println("Parsed date: " + parsedDate);
        } catch (ParseException e) {
            System.out.println("Parse exception: " + e.getMessage());
        }
    }
}


---------- END SOURCE ----------