/etc/init/hwclock-save.conf for Ubuntu 12.04 with ACPI Wakealarm enabled

hwclock-save.conf

# hwclock-save - save system clock to hardware clock
#
# This task saves the time from the system clock back to the hardware
# clock on shutdown.

description     "save system clock to hardware clock"

start on runlevel [06]

task

script
    . /etc/default/rcS
    [ "$UTC" = "yes" ] && tz="--utc" || tz="--localtime"
    [ "$BADYEAR" = "yes" ] && badyear="--badyear"
    ACPITIME=`cat /sys/class/rtc/rtc0/wakealarm`
    exec hwclock --rtc=/dev/rtc0 --systohc $tz --noadjfile $badyear
    echo $ACPITIME > /sys/class/rtc/rtc0/wakealarm
end script