class GregorianCalendarConverter implements AtlasConverter<GregorianCalendar> {

    @AtlasConversionInfo(sourceType = FieldType.DATE_TIME_TZ, targetType = FieldType.DATE_TIME)
    public Date toDate(GregorianCalendar calendar) {
        return zdtConverter.toDate(calendar.toZonedDateTime());
    }

}