FreeSource : NickGrechukh/AcpiSetAlarm

в /proc/acpi/alarm писать нужно время в таймзоне биоса.

. /etc/init.d/functions
SourceIfNotEmpty /etc/sysconfig/clock

valid_date(){
        biosdate=$(date $utcswitch -d "$timespec $tz") && echo Setting alarm on $biosdate ...
}

write_alarm(){
        if [ -w /proc/acpi/alarm ] ; then
                date $utcswitch -d "$timespec $tz" +'%Y-%M-%d %H:%M:%S' > /proc/acpi/alarm
        else
                echo "/proc/acpi/alarm isn't writable!"
                return -1
        fi
}

tz=`date +%Z`

if [ "$*" == "" ]; then
        read timespec || exit 0
else
        timespec="$*"
fi

[ "$UTC" == "yes" ] && utcswitch="-u" || utcswitch=""

if valid_date && write_alarm; then
        echo "alarm installed, test it (remember that is BIOS timezone): "
        echo -n "       " ; cat /proc/acpi/alarm
else
        echo Can\'t setup alarm!
        exit -1
fi