[Unit]
Description=Timesyncd persistent configuration
Requires=mnt-overlay.mount
After=mnt-overlay.mount systemd-tmpfiles-setup.service
Before=systemd-timesyncd.service

[Mount]
What=/mnt/overlay/etc/systemd/timesyncd.conf
Where=/etc/systemd/timesyncd.conf
Type=none
Options=bind

[Install]
WantedBy=hassos-bind.target