Time Conversion in java from SGT to UTC not working for 12:35:42

Question

Trying to convert Singapore Time to UTc and need the result in OffsetDateTime. The below code works for me for all scenerios except one for 12:35..... for 12:00 noon it is somehow giving wrong results. Should be giving 8th Feb 04:35 morning but instead giving 7th Feb 16:35 . what could be the way around it

Code snippets as below

    if (dbTime == null) {
        return null;
    }
    SimpleDateFormat dateTimeFormatter = new SimpleDateFormat("yyyy-MM-dd hh:mm:ss");
    dateTimeFormatter.setTimeZone(TimeZone.getTimeZone(ZoneId.of("Asia/Singapore")));
    Instant instant = null;
    try {
        dateTimeFormatter.parse(dbTime);
        instant = dateTimeFormatter.parse(dbTime).toInstant();
    } catch (ParseException e) {
        LOGGER.warn("Could not parse ({}) to valid DateTime ", dbTime, e);
        return null;
    }
    OffsetDateTime offsetDateTime = instant.atOffset(ZoneOffset.UTC);
    return offsetDateTime;
}

@Test
void canConvertSGTToUTC() {
    String sqlDate = "2023-02-08 12:35:45.0";
    var result = dateParser.parseToOffsetDateTime(sqlDate);
    assertEquals( "2023-02-08T04:35:45Z", result.toString());
}

SGT or Asia/Singapore is local system time from the servers.

Answer 1

use the "HH:mm:ss" format where "H" is 24hr format. "h" is 12hr format. should solve your problem