/usr/lib/systemd/system/ Current File: //usr/lib/systemd/system/unbound-anchor.timer

[Unit]
Description=daily update of the root trust anchor for DNSSEC
Documentation=man:unbound-anchor(8)

[Timer]
# Current DNSKEY TTL in root zone is 172800 seconds, i.e. 172800/60/60/24 = 2 days.
# It means that unboud-anchor should be run at least once a day.
OnCalendar=daily
Persistent=true
AccuracySec=24h

[Install]
WantedBy=timers.target