Run CRON job everyday at specific time

Question

Right now i am running my cron job everyday at 3.00PM

0    15    *    *    *

But I want to run my cron job twice in a day. 10.30AM and 2.30PM

0    30 10    *    *    *

I believe this command will run at 10.30AM. How should i run it in 2.30PM?

Answer 1

Cron utility is an effective way to schedule a routine background job at a specific time and/or day on an on-going basis.

Linux Crontab Format

MIN HOUR DOM MON DOW CMD

Example::Scheduling a Job For a Specific Time

The basic usage of cron is to execute a job in a specific time as shown below. This will execute the Full backup shell script (full-backup) on 10th June 08:30 AM.

Please note that the time field uses 24 hours format. So, for 8 AM use 8, and for 8 PM use 20.

30 08 10 06 * /home/yourname/full-backup

• 30 – 30th Minute
• 08 – 08 AM
• 10 – 10th Day
• 06 – 6th Month (June)
• *– Every day of the week

In your case, for 2.30PM,

30 14 * * * YOURCMD

1. 30 – 30th Minute
2. 14 – 2PM
3. *– Every day
4. *– Every month
5. *– Every day of the week

To know more about cron, visit this website.

Answer 2

From cron manual http://man7.org/linux/man-pages/man5/crontab.5.html:

Lists are allowed. A list is a set of numbers (or ranges) separated by commas. Examples: "1,2,5,9", "0-4,8-12".

So in this case it would be:

30 10,14 * * *

Answer 3

you can write multiple lines in case of different minutes, for example you want to run at 10:01 AM and 2:30 PM

1 10 * * * php -f /var/www/package/index.php controller function

30 14 * * * php -f /var/www/package/index.php controller function

but the following is the best solution for running cron multiple times in a day as minutes are same, you can mention hours like 10,30 .

30 10,14 * * * php -f /var/www/package/index.php controller function