[Unit]
Description=Daily pre-update maintenance notification, fires before apt-daily-upgrade.timer's window

[Timer]
# Fixed, unrandomized time - must fire safely before the earliest possible
# start of apt-daily-upgrade.timer. Default apt-daily-upgrade.timer ships as
# OnCalendar=*-*-* 6:00 with RandomizedDelaySec=60m (actual run: 06:00-07:00).
# If your apt-daily-upgrade.timer differs (check with
# `systemctl cat apt-daily-upgrade.timer`), adjust the time below to keep a
# comfortable lead.
OnCalendar=*-*-* 05:00
Persistent=true

[Install]
WantedBy=timers.target