Topic 108 · Essential System Services
108.1 Maintain system time
Step 1 of 9 · weight 3
Why time matters
The system clock is shared by logs, cron, TLS certificates, file timestamps, and anything that rejects a skewed clock. If it is wrong, the machine still runs, but the evidence it leaves is hard to trust.
- Log lines and journal entries are ordered by this clock.
- Cron and systemd timers fire from it.
- Certificate validity and make both compare against it.
Exam note
108.1 is about keeping that clock correct and synchronized. The later nodes are the tools the objective names.