Merge pull request #20301 from sftim/20200413_fix_cronjob_timezone_note

Note CronJob timezone comes from system timezone

Author: k8s-ci-robot

content/en/docs/concepts/workloads/controllers/cron-jobs.md

@@ -17,9 +17,14 @@ A _CronJob_ creates {{< glossary_tooltip term_id="job" text="Jobs" >}} on a repe
 One CronJob object is like one line of a _crontab_ (cron table) file. It runs a job periodically
 on a given schedule, written in [Cron](https://en.wikipedia.org/wiki/Cron) format.
 
-{{< note >}}
-All **CronJob** `schedule:` times are denoted in UTC.
-{{< /note >}}
+{{< caution >}}
+All **CronJob** `schedule:` times are based on the timezone of the
+{{< glossary_tooltip term_id="kube-controller-manager" text="kube-controller-manager" >}}.
+
+If your control plane runs the kube-controller-manager in Pods or bare
+containers, the timezone set for the kube-controller-manager container determines the timezone
+that the cron job controller uses.
+{{< /caution >}}
 
 When creating the manifest for a CronJob resource, make sure the name you provide
 is a valid [DNS subdomain name](/docs/concepts/overview/working-with-objects/names#dns-subdomain-names).