[ghaf@ghaf-host:~]$ udevadm info -q property -p /sys/class/rtc/rtc0 | grep -E 'DEVNAME|SUBSYSTEM|SYSTEMD_WANTS'
DEVNAME=/dev/rtc0
SUBSYSTEM=rtc
SYSTEMD_WANTS=ghaf-seed-time-from-rtc@rtc0.service

[ghaf@ghaf-host:~]$ systemctl status ghaf-seed-time-from-rtc@rtc0.service --no-pager -l
○ ghaf-seed-time-from-rtc@rtc0.service - Seed system time from plausible RTC value (rtc0)
     Loaded: loaded (/etc/systemd/system/ghaf-seed-time-from-rtc@.service; static)
     Active: inactive (dead) since Thu 2024-12-19 21:40:18 UTC; 1 year 2 months ago
 Invocation: 7f00798988b04d839846885fbc521db8
    Process: 839 ExecStart=/nix/store/w7zcgwi15sn00ax8jhwfhaalrzinf12s-unit-script-ghaf-seed-time-from-rtc_-start/bin/ghaf-seed-time-from-rtc_-start rtc0 (code=exited, status=0/SUCCESS)
   Main PID: 839 (code=exited, status=0/SUCCESS)
         IP: 0B in, 0B out
         IO: 12K read, 0B written
   Mem peak: 1.7M
        CPU: 12ms

Dec 19 21:40:18 ghaf-host systemd[1]: Starting Seed system time from plausible RTC value (rtc0)...
Dec 19 21:40:18 ghaf-host ghaf-seed-time-from-rtc_-start[839]: RTC seed skipped: RTC epoch 34 below minimum 1704067200
Dec 19 21:40:18 ghaf-host systemd[1]: ghaf-seed-time-from-rtc@rtc0.service: Deactivated successfully.
Dec 19 21:40:18 ghaf-host systemd[1]: Finished Seed system time from plausible RTC value (rtc0).

[ghaf@ghaf-host:~]$ systemctl status systemd-timesyncd.service --no-pager -l
● systemd-timesyncd.service - Network Time Synchronization
     Loaded: loaded (/etc/systemd/system/systemd-timesyncd.service; enabled; preset: ignored)
    Drop-In: /nix/store/ql6846l4zqmn96hvaxc8vclisc17hi71-system-units/systemd-timesyncd.service.d
             └─overrides.conf
     Active: active (running) since Thu 2024-12-19 21:40:15 UTC; 1 year 2 months ago
 Invocation: bc92b6550b754dcb88d82742e3ddb1a8
       Docs: man:systemd-timesyncd.service(8)
   Main PID: 456 (systemd-timesyn)
     Status: "Contacted time server 89.36.162.11:123 (2.nixos.pool.ntp.org)."
         IP: 152B in, 2.7K out
         IO: 3.6M read, 0B written
      Tasks: 2 (limit: 36475)
     Memory: 5.6M (peak: 6.3M)
        CPU: 71ms
     CGroup: /system.slice/systemd-timesyncd.service
             └─456 /nix/store/0amh70w52yzrn3ccgw0vn0ani1qxwqx5-host-systemd-aarch64-unknown-linux-gnu-258.3/lib/systemd/systemd-timesyncd

Dec 19 21:40:24 ghaf-host systemd-timesyncd[456]: Network configuration changed, trying to establish connection.
Dec 19 21:40:24 ghaf-host systemd-timesyncd[456]: Network configuration changed, trying to establish connection.
Dec 19 21:40:24 ghaf-host systemd-timesyncd[456]: Network configuration changed, trying to establish connection.
Dec 19 21:40:24 ghaf-host systemd-timesyncd[456]: Network configuration changed, trying to establish connection.
Dec 19 21:40:24 ghaf-host systemd-timesyncd[456]: Network configuration changed, trying to establish connection.
Dec 19 21:40:24 ghaf-host systemd-timesyncd[456]: Network configuration changed, trying to establish connection.
Dec 19 21:40:24 ghaf-host systemd-timesyncd[456]: Network configuration changed, trying to establish connection.
Dec 19 21:40:24 ghaf-host systemd-timesyncd[456]: Network configuration changed, trying to establish connection.
Mar 11 10:38:52 ghaf-host systemd-timesyncd[456]: Contacted time server 89.36.162.11:123 (2.nixos.pool.ntp.org).
Mar 11 10:38:52 ghaf-host systemd-timesyncd[456]: Initial clock synchronization to Wed 2026-03-11 10:38:52.642383 UTC.

[ghaf@ghaf-host:~]$ ls -ld /var/lib/systemd/timesync && stat /var/lib/systemd/timesync/clock
drwxr-xr-x 2 systemd-timesync systemd-timesync 4096 Dec 19  2024 /var/lib/systemd/timesync
  File: /var/lib/systemd/timesync/clock
  Size: 0               Blocks: 0          IO Block: 4096   regular empty file
Device: 179,1   Inode: 2097161     Links: 1
Access: (0644/-rw-r--r--)  Uid: (  154/systemd-timesync)   Gid: (  154/systemd-timesync)
Access: 2026-03-11 10:40:29.187103000 +0000
Modify: 2026-03-11 10:40:29.187103000 +0000
Change: 2026-03-11 10:40:29.181186157 +0000
 Birth: 2024-12-19 21:28:03.804000000 +0000

[ghaf@ghaf-host:~]$ timedatectl show -p NTPSynchronized -p TimeUSec
NTPSynchronized=yes
TimeUSec=Wed 2026-03-11 10:41:12 UTC

[ghaf@ghaf-host:~]$ journalctl -b --no-pager | grep -E 'nvvrs-pseq-rtc|setting system clock|Time jumped backwards|RTC seed'
Dec 19 21:40:16 ghaf-host kernel: nvvrs-pseq-rtc nvvrs-pseq-rtc: registered as rtc0
Dec 19 21:40:18 ghaf-host ghaf-seed-time-from-rtc_-start[839]: RTC seed skipped: RTC epoch 34 below minimum 1704067200