Merge pull request #29455 from cndoit18/feat/add-cronjob-timezone

[en]: description of the cronjob schedule timezone

Author: k8s-ci-robot

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

@@ -10,13 +10,15 @@ weight: 80
 
 <!-- overview -->
 
-{{< feature-state for_k8s_version="v1.21" state="stable" >}}
+{{< feature-state for_k8s_version="v1.22" state="stable" >}}
 
 A _CronJob_ creates {{< glossary_tooltip term_id="job" text="Jobs" >}} on a repeating schedule.
 
 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.
 
+In addition, the CronJob schedule supports timezone handling, you can specify the timezone by adding "CRON_TZ=<time zone>" at the beginning of the CronJob schedule, and it is recommended to always set `CRON_TZ`.
+
 {{< caution >}}
 All **CronJob** `schedule:` times are based on the timezone of the
 {{< glossary_tooltip term_id="kube-controller-manager" text="kube-controller-manager" >}}.
@@ -53,15 +55,16 @@ takes you through this example in more detail).
 ### Cron schedule syntax
 
 ```
-# ┌───────────── minute (0 - 59)
-# │ ┌───────────── hour (0 - 23)
-# │ │ ┌───────────── day of the month (1 - 31)
-# │ │ │ ┌───────────── month (1 - 12)
-# │ │ │ │ ┌───────────── day of the week (0 - 6) (Sunday to Saturday;
-# │ │ │ │ │                                   7 is also Sunday on some systems)
-# │ │ │ │ │
-# │ │ │ │ │
-# * * * * *
+#      ┌────────────────── timezone (optional)
+#      |      ┌───────────── minute (0 - 59)
+#      |      │ ┌───────────── hour (0 - 23)
+#      |      │ │ ┌───────────── day of the month (1 - 31)
+#      |      │ │ │ ┌───────────── month (1 - 12)
+#      |      │ │ │ │ ┌───────────── day of the week (0 - 6) (Sunday to Saturday;
+#      |      │ │ │ │ │                                   7 is also Sunday on some systems)
+#      |      │ │ │ │ │
+#      |      │ │ │ │ │
+# CRON_TZ=UTC * * * * *
 ```
 
 
@@ -75,9 +78,9 @@ takes you through this example in more detail).
 
 
 
-For example, the line below states that the task must be started every Friday at midnight, as well as on the 13th of each month at midnight:
+For example, the line below states that the task must be started every Friday at midnight, as well as on the 13th of each month at midnight(in UTC):
 
-`0 0 13 * 5`
+`CRON_TZ=UTC 0 0 13 * 5`
 
 To generate CronJob schedule expressions, you can also use web tools like [crontab.guru](https://crontab.guru/).