gistfile1.java

    private DateTime get6HourTimeSlice(DateTime dateTime) {
        Chronology chronology = GregorianChronology.getInstance();
        DateTimeField hourField = chronology.hourOfDay();
        DividedDateTimeField dividedField = new DividedDateTimeField(hourField, DateTimeFieldType.clockhourOfDay(), 6);
        long timestamp = dividedField.roundFloor(dateTime.getMillis());

        return new DateTime(timestamp);
    }