systemd/units/hwclock-load.service

#  This file is part of systemd.
#
#  systemd is free software; you can redistribute it and/or modify it
#  under the terms of the GNU General Public License as published by
#  the Free Software Foundation; either version 2 of the License, or
#  (at your option) any later version.

[Unit]
Description=Apply System Clock UTC Offset
DefaultDependencies=no
Wants=time-sync.target
Conflicts=shutdown.target
After=systemd-readahead-collect.service systemd-readahead-replay.service
Before=sysinit.target shutdown.target udev.service time-sync.target

[Service]
Type=oneshot
RemainAfterExit=yes
ExecStart=/sbin/hwclock --systz
StandardOutput=syslog

# Note the weird semantics of hwclock and the kernel here: the first
# settimeofday() invocation from userspace is special and may be used
# to set the offset from UTC of the system clock. It is independent
# of any specific RTC device. This is mostly a crufty hack to support
# legacy operating systems which insist on storing local time in the
# RTC.

# Note that we do not run --hctosys here, we assume the kernel
# includes a compiled in RTC module which is used to initialize the
# system time as part of kernel setup.

[Install]
WantedBy=sysinit.target