manual
    visudo
    root crontab
    sudo nano /lib/udev/hwclock-set
        comment out and add note
            # commented out manually to use rtc
            # if [ -e /run/systemd/system ] ; then
            #  exit 0
            # fi
        Also comment out the two lines
            #  /sbin/hwclock --rtc=$dev --systz --badyear
            and
            # /sbin/hwclock --rtc=$dev --systz