ADD: Added two mds to compare AI generated manuals

timer-as-service.md

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+## Timer as a service — quick manual
+
+This short guide shows how to set up a systemd timer that runs a job, how to enable/start it, and how to list and inspect existing timers.
+
+### Checklist
+- Create a `.service` that performs the work
+- Create a corresponding `.timer` with the schedule
+- Reload systemd, enable and start the timer
+- List timers and inspect logs for failures
+
+### Units: example
+System-wide units live under `/etc/systemd/system`. For per-user timers use `~/.config/systemd/user/` and `systemctl --user`.
+
+Create `/etc/systemd/system/my-job.service`:
+```ini
+[Unit]
+Description=My scheduled job
+
+[Service]
+Type=oneshot
+ExecStart=/usr/local/bin/my-job.sh
+```
+
+Create `/etc/systemd/system/my-job.timer`:
+```ini
+[Unit]
+Description=Run my-job every day at 02:30
+
+[Timer]
+OnCalendar=*-*-* 02:30:00
+Persistent=true
+
+[Install]
+WantedBy=timers.target
+```
+
+Notes:
+- `Type=oneshot` is appropriate for short scripts that exit.
+- `Persistent=true` makes missed runs (while the machine was down) run on next boot.
+
+### Install, enable and start
+After creating or editing unit files run:
+```bash
+sudo systemctl daemon-reload
+sudo systemctl enable --now my-job.timer
+```
+
+For a user timer (no sudo):
+```bash
+systemctl --user daemon-reload
+systemctl --user enable --now my-job.timer
+```
+
+### List existing timers
+Show all timers (system):
+```bash
+systemctl list-timers --all
+```
+This shows UNIT, ACTIVATES, NEXT, LEFT, LAST and PASSED columns. `NEXT` is the next trigger time.
+
+User timers:
+```bash
+systemctl --user list-timers --all
+```
+
+Filter for a specific timer:
+```bash
+systemctl list-timers --all | grep my-job
+systemctl status my-job.timer
+systemctl status my-job.service
+```
+
+### Logs and debugging
+View recent service logs:
+```bash
+journalctl -u my-job.service -b
+```
+View timer logs:
+```bash
+journalctl -u my-job.timer -b
+```
+
+If the job never ran, check:
+- `systemctl status my-job.timer` for errors
+- `ExecStart` path and executable permissions
+- run the `ExecStart` command manually to verify behavior
+- `OnCalendar` syntax (see `man systemd.time`)
+
+Common fixes:
+- `sudo systemctl daemon-reload` after edits
+- ensure `my-job.service` is reachable and executable by the user that runs it
+- for user timers, make sure the user session is running or enable linger if run outside a login session
+
+### Helpful examples
+Run the job 10 seconds after boot and every 5 minutes:
+```ini
+[Timer]
+OnBootSec=10s
+OnUnitActiveSec=5min
+Persistent=true
+```
+
+Use environment variables inside the service:
+```ini
+[Service]
+Environment=ENVIRONMENT=production
+EnvironmentFile=/etc/default/my-job
+```
+
+### Remove or disable a timer
+```bash
+sudo systemctl disable --now my-job.timer
+sudo rm /etc/systemd/system/my-job.timer /etc/systemd/system/my-job.service
+sudo systemctl daemon-reload
+```
+
+### Quick troubleshooting checklist
+- Confirm unit files are syntactically correct
+- Check permissions and shebang on the script
+- `journalctl -u <unit>` for errors
+- For user timers: check `systemctl --user status` and enable linger with `loginctl enable-linger <user>` if needed
+
+---
+This file provides a compact reference; tell me if you want a tailored example script and a ready-to-install pair of units added to the repo.