public static ZoneOffset calculateZoneOffset(Object usertimeZone, ZoneId defaultZoneId) {
        ZoneId zoneId = calculateZoneId(usertimeZone, defaultZoneId);
        LocalDateTime now = LocalDateTime.now();
        return zoneId.getRules().getOffset(now);
    }
Write the value of Calendar options

@param context
@param uicalendar component
@param optionName the name of an option
@param values the List values of an option
@param pattern the pattern for formatting
@throws IOException if writer is null
primefaces/src/main/java/org/primefaces/util/CalendarUtils.java