diff --git a/nas/nas-install.md b/nas/nas-install.md
index bd3665e..4fc6a03 100644
--- a/nas/nas-install.md
+++ b/nas/nas-install.md
@@ -729,6 +729,7 @@ Then test-restore one instance before ticking the gate in
 | 04:00 | nas | local copy of nas instances → `nasbackup` (`tank/backup/nas`) |
 | 05:00 | nas | pull `ks4:*` → `ks4backup` (after FTTH) |
 | 05:30 | nuc | apt upgrade all containers |
+| 06:00 | nas | apt upgrade all containers (`incus-container-upgrade.sh`, added 2026-09-01; also refreshes `user.os`) |
 | Mon ~00:12 | nas | `zfs-scrub-weekly@tank.timer` / `@incus.timer` (systemd, not cron) |
 
 Staggered around ks4's own 01:00 / 05:00 jobs.