Recently i upgraded my mysql-connector from 5.1.47 to 8.0.33. After that, i met an error:

Caused by: java.sql.SQLException: HOUR_OF_DAY: 0 -> 1 at com.mysql.cj.jdbc.exceptions.SQLError.createSQLException(SQLError.java:130) ~[mysql-connector-j-8.0.33.jar:8.0.33] at com.mysql.cj.jdbc.exceptions.SQLError.createSQLException(SQLError.java:98) ~[mysql-connector-j-8.0.33.jar:8.0.33] at com.mysql.cj.jdbc.exceptions.SQLError.createSQLException(SQLError.java:90) ~[mysql-connector-j-8.0.33.jar:8.0.33] at com.mysql.cj.jdbc.exceptions.SQLError.createSQLException(SQLError.java:64) ~[mysql-connector-j-8.0.33.jar:8.0.33] at com.mysql.cj.jdbc.exceptions.SQLError.createSQLException(SQLError.java:74) ~[mysql-connector-j-8.0.33.jar:8.0.33] at com.mysql.cj.jdbc.exceptions.SQLExceptionsMapping.translateException(SQLExceptionsMapping.java:85) ~[mysql-connector-j-8.0.33.jar:8.0.33] at com.mysql.cj.jdbc.result.ResultSetImpl.getTimestamp(ResultSetImpl.java:947) ~[mysql-connector-j-8.0.33.jar:8.0.33] at com.mysql.cj.jdbc.result.ResultSetImpl.getTimestamp(ResultSetImpl.java:985) ~[mysql-connector-j-8.0.33.jar:8.0.33] at com.zaxxer.hikari.pool.HikariProxyResultSet.getTimestamp(HikariProxyResultSet.java) ~[HikariCP-4.0.3.jar:na] at org.hibernate.type.descriptor.sql.TimestampTypeDescriptor$2.doExtract(TimestampTypeDescriptor.java:84) ~[hibernate-core-5.6.15.Final.jar:5.6.15.Final] at org.hibernate.type.descriptor.sql.BasicExtractor.extract(BasicExtractor.java:47) ~[hibernate-core-5.6.15.Final.jar:5.6.15.Final] at org.hibernate.type.AbstractStandardBasicType.nullSafeGet(AbstractStandardBasicType.java:257) ~[hibernate-core-5.6.15.Final.jar:5.6.15.Final] at org.hibernate.type.AbstractStandardBasicType.nullSafeGet(AbstractStandardBasicType.java:253) ~[hibernate-core-5.6.15.Final.jar:5.6.15.Final] at org.hibernate.type.AbstractStandardBasicType.nullSafeGet(AbstractStandardBasicType.java:243) ~[hibernate-core-5.6.15.Final.jar:5.6.15.Final] at org.hibernate.type.AbstractStandardBasicType.hydrate(AbstractStandardBasicType.java:329) ~[hibernate-core-5.6.15.Final.jar:5.6.15.Final] at org.hibernate.persister.entity.AbstractEntityPersister.hydrate(AbstractEntityPersister.java:3214) ~[hibernate-core-5.6.15.Final.jar:5.6.15.Final] at org.hibernate.persister.entity.Loadable.hydrate(Loadable.java:94) ~[hibernate-core-5.6.15.Final.jar:5.6.15.Final] at org.hibernate.loader.plan.exec.process.internal.EntityReferenceInitializerImpl.loadFromResultSet(EntityReferenceInitializerImpl.java:342) ~[hibernate-core-5.6.15.Final.jar:5.6.15.Final] ... 113 common frames omitted

By investigating this error, I got that the new mysql driver would do some converting and my dataset contains the date ‘1916-05-01 00:00 00’. According to wikipedia, the first nation-wide daylight saving time implementations were by the German and Austro-Hungarian Empires, both starting on 30 April 1916. So it may be thinking that it can’t convert ‘1916-05-01 00:00 00’ to timestamp since ‘1916-05-01 00:00 00’ is ‘non-existent’, only ‘1916-05-01 01:00 00’.
I decided to find out all of these ‘non-existent’ dates in timezone ‘Europe/Amsterdam’. Here is how i did:

public static void main(String[] args) throws ParseException {
        SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd");
        Calendar start = Calendar.getInstance();
        Calendar end = Calendar.getInstance();
        start.setTime(sdf.parse("1900-01-01"));
        end.setTime(sdf.parse("2025-01-01"));
        List<String> errorItems = new ArrayList<>();
        while (!start.after(end)) {
            try {
                Calendar calendar = Calendar.getInstance(TimeZone.getTimeZone("Europe/Amsterdam"), Locale.US);
                calendar.setLenient(false);
                calendar.set(start.get(Calendar.YEAR), start.get(Calendar.MONTH), start.get(Calendar.DAY_OF_MONTH), 0, 0, 0);
                Timestamp ts = new Timestamp(calendar.getTimeInMillis());
                System.out.println(ts);
            } catch (IllegalArgumentException e) {
                errorItems.add(sdf.format(start.getTime()));
            }
            start.add(Calendar.DAY_OF_YEAR, 1);
        }
        System.out.println("error date: " + errorItems);
    }

The result is: [1914-11-08, 1916-05-01]

The ‘1916-05-01’ I’ve already understood, but why ‘1914-11-08’? The DST even did not exist in 1914. Does anyone have any idea?

I’d like to know why I can’t get the Timestamp of the date ‘1914-11-08 00:00:00’ in timezone ‘Europe/Amsterdam’.