public void setDateAndTime(LocalDateTime ldt) {
        this.dat = new DateAndTime(
            ((short) (ldt.getYear() - 2000)),
            (short) ldt.getMonthValue(),
            (short) ldt.getDayOfMonth(),
            (short) ldt.getHour(),
            (short) ldt.getMinute(),
            (short) ldt.getSecond(),
            (short) TimeUnit.NANOSECONDS.toMillis(ldt.getNano()),
            (byte) ldt.getDayOfWeek().plus(1).getValue()
        );
    }
It seems reading CLK and CLKF are convenience ways of reading the PLCs Clock Data
- CLK seems to read the clock data via structured value (year, month, day, hour, ...)
- CLKF seems to read a formatted or extended format.
plc4j/drivers/s7/src/main/java/org/apache/plc4x/java/s7/readwrite/tag/S7ClkTag.java