add cronjobs to examples

examples/cronjob.md

@@ -8,5 +8,61 @@ editor: markdown
 dateCreated: 2023-06-27T08:28:13.676Z
 ---
 
-# Header
-Your content here
+# How to use cronjobs
+
+This guide provides examples on how to use cronjob to automate tasks.
+
+## Get Started
+
+- Begin by opening a terminal and running the following command:
+
+```bash
+crontab -e
+```
+
+This command will open the crontab file in the nano text editor.
+
+- Next, you need to define the cronjob. Add the following lines to the file:
+
+```bash
+* * * * * <command>
+```
+
+- Finally, you can save the file by pressing `Ctrl + X` and then `Y`.
+
+## Syntax
+
+```bash
+* <- minute (0-59)
+  * <- hour (0-23)
+    * <- day of month (1-31)
+      * <- month (1-12)
+        * <- day of week (0-6) (Sunday=0)
+          <command>
+```
+
+## Examples
+
+### Run a command every minute
+
+```bash
+* * * * * <command>
+```
+
+### Run a command every 5 minutes
+
+```bash
+*/5 * * * * <command>
+```
+
+### Run a command every hour
+
+```bash
+0 * * * * <command>
+```
+
+### Run a command every day at midnight
+
+```bash
+0 0 * * * <command>
+```