[Demonstration 1]

[Buggy Method]
public static String getFormattedDateStr(String utc) {
    DateTime dateTime = new DateTime(utc, DateTimeZone.UTC);
    DateTimeFormatter formatter = DateTimeFormat.shortDateTime().withLocale(Locale.US);
    return formatter.print(dateTime);
}

[Buggy Hunk]
DateTime dateTime = new DateTime(utc, DateTimeZone.UTC);

[Patch]
DateTime dateTime = (new DateTime(utc, DateTimeZone.UTC)).toDateTime(DateTimeZone.getDefault());

[Demonstration 2]

[Buggy Method]
private String generateStatus() {
    DateTime today = new DateTime();
    if (isFinished()) {
        return "finished";
    } else if (isBeyondTheForeseen(today)) {
        return "late";
    } else if (isStarted(today)) {
        return "doing";
    }
    return "waiting";
}

[Buggy Hunk]
DateTime today = new DateTime();

[Patch]
DateTime today = new DateTime().withMillisOfDay(0);

[Demonstration 3]

[Buggy Method]
protected DateTime getLastSunday(int year, int month, int day) {
    DateTime lastDay = new DateTime(year, month, day, 0, 0);
    logger.info("lastDay: " + lastDay.toString());
    int dow = lastDay.getDayOfWeek();
    logger.info("dow: " + dow);
    if (dow == 7) {
        return lastDay;
    } else {
        DateTime result = lastDay.minusDays(dow);
        logger.info("result: " + result.toString());
        return result;
    }
}

[Buggy Hunk]
DateTime lastDay = new DateTime(year, month, day, 0, 0);

[Patch]
DateTime lastDay = new DateTime(year, month, day, 0, 0, DateTimeZone.UTC);