From b4ba582255d403811b134c75d5bdcc9aa91976d3 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?P=C4=93teris=20Caune?= <cuu508@gmail.com>
Date: Mon, 31 Aug 2020 12:51:24 +0300
Subject: [PATCH] Docs: add the "Viewing cron logs using journalctl" section

---
 templates/docs/monitoring_cron_jobs.html | 16 ++++++++++++++++
 templates/docs/monitoring_cron_jobs.md   | 21 +++++++++++++++++++++
 2 files changed, 37 insertions(+)

diff --git a/templates/docs/monitoring_cron_jobs.html b/templates/docs/monitoring_cron_jobs.html
index 72e5bbd7..9672de60 100644
--- a/templates/docs/monitoring_cron_jobs.html
+++ b/templates/docs/monitoring_cron_jobs.html
@@ -79,6 +79,9 @@ Transient error is a timeout or an HTTP 5xx response code.</dd>
 <dd>Redirect curl's stdout to /dev/null (error messages still go to stderr).</dd>
 </dl>
 <h2>Looking up Your Machine's Time Zone</h2>
+<p>If your cron job consistently pings SITE_NAME an hour early or an hour late,
+the likely cause is a timezone mismatch: your machine may be using a different timezone
+than what is configured on SITE_NAME.</p>
 <p>On modern GNU/Linux systems, you can look up the time zone using the
 <code>timedatectl status</code> command and looking for "Time zone" in its output:</p>
 <div class="text highlight"><pre><span></span><code>$ timedatectl status
@@ -90,4 +93,17 @@ Transient error is a timeout or an HTTP 5xx response code.</dd>
 </span>System clock synchronized: yes
               NTP service: active
           RTC in local TZ: no
+</code></pre></div>
+
+
+<h2>Viewing cron logs using <code>journalctl</code></h2>
+<p>On a systemd-based system, you can use the <code>journalctl</code> utility to see system logs,
+including logs from the cron daemon.</p>
+<p>To see live logs:</p>
+<div class="bash highlight"><pre><span></span><code>journalctl -f
+</code></pre></div>
+
+
+<p>To see logs from e.g. the last hour, and only from the cron daemon:</p>
+<div class="bash highlight"><pre><span></span><code>journalctl --since <span class="s2">&quot;1 hour ago&quot;</span> -t CRON
 </code></pre></div>
\ No newline at end of file
diff --git a/templates/docs/monitoring_cron_jobs.md b/templates/docs/monitoring_cron_jobs.md
index cf8d017a..2d3abb91 100644
--- a/templates/docs/monitoring_cron_jobs.md
+++ b/templates/docs/monitoring_cron_jobs.md
@@ -85,6 +85,10 @@ suit your needs.
 
 ## Looking up Your Machine's Time Zone
 
+If your cron job consistently pings SITE_NAME an hour early or an hour late,
+the likely cause is a timezone mismatch: your machine may be using a different timezone
+than what is configured on SITE_NAME.
+
 On modern GNU/Linux systems, you can look up the time zone using the
 `timedatectl status` command and looking for "Time zone" in its output:
 
@@ -99,3 +103,20 @@ System clock synchronized: yes
               NTP service: active
           RTC in local TZ: no
 ```
+
+## Viewing cron logs using `journalctl`
+
+On a systemd-based system, you can use the `journalctl` utility to see system logs,
+including logs from the cron daemon.
+
+To see live logs:
+
+```bash
+journalctl -f
+```
+
+To see logs from e.g. the last hour, and only from the cron daemon:
+
+```bash
+journalctl --since "1 hour ago" -t CRON
+```