How to Schedule a Cron Job to Run 4Th Week of the Year

How can I create Cron Expression which works between particular times

Some things you cannot do in a single expression and you might consider to use two:

# Example of job definition:
# .--------------------- minute (0 - 59)
# |       .------------- hour (0 - 23)
# |       |  .---------- day of month (1 - 31)
# |       |  |  .------- month (1 - 12) OR jan,feb,mar,apr ...
# |       |  |  |  .---- day of week (0 - 6) (Sunday=0 or 7)
# |       |  |  |  |
# *       *  *  *  *   command to be executed
# This runs on 7:30, 7:40, 7:50
 30/10    7  *  * 1-5  command
# This runs on 8:00, 8:10, 8:20
 0-20/10  8  *  * 1-5  command

Another way you could attempt this is by using a test.

# Example of job definition:
# .--------------------- minute (0 - 59)
# |      .------------- hour (0 - 23)
# |      |   .---------- day of month (1 - 31)
# |      |   |  .------- month (1 - 12) OR jan,feb,mar,apr ...
# |      |   |  |  .---- day of week (0 - 6) (Sunday=0 or 7)
# |      |   |  |  |
# *      *   *  *  *   command to be executed
*/10    7,8  *  * 1-5  testcmd && command

Where testcmd is an executable script that could look like:

#!/usr/bin/env bash
hours=$(date "+%H")
minutes=$(date "+%M")
(( hours == 7 && minutes >= 30)) || (( hours == 8 && minutes <= 20 ))

Other examples of this trick can be found here:

• Cron expression to run every N minutes
• How to schedule a Cron job to run 4th week of the year
• how to set cronjob for 2 days?

Cron Job to run on a range of days only on a particular day of week

This is the crontab format:

* * * * *
| | | | |
| | | | +---- Day of the Week   (range: 0-6, 0 standing for Sunday)
| | | +------ Month of the Year (range: 1-12)
| | +-------- Day of the Month  (range: 1-31)
| +---------- Hour              (range: 0-23)
+------------ Minute            (range: 0-59)

Ubuntu man 5 crontab says:

  field          allowed values
  -----          --------------
  minute         0-59
  hour           0-23
  day of month   1-31
  month          1-12 (or names, see below)
  day of week    0-7 (0 or 7 is Sun, or use names)

So, this should work for you:

0 0 2-31 * 0         /home/ubuntu/x.h
0 0 2-31 * 1-6       /home/ubuntu/y.h

I'm not sure why 7 would run on Saturday--is your system time accurate and in the right timezone?

Edit: Ah, yes, unfortunately you cannot specify both the day of the week and the day of the month. From man 5 crontab:

Note: The day of a command's execution can be specified by two fields — day of month, and day of week. If both fields are restricted (i.e., aren't *), the command will be run when either field matches the current time. For example, ``30 4 1,15 * 5'' would cause a command to be run at 4:30 am on the 1st and 15th of each month, plus every Friday. One can, however, achieve the desired result by adding a test to the command (see the last example in EXAMPLE CRON FILE below).

So, the answer is:

0 0 2-31 * *       test $(date +\%u) -eq 7 && /home/ubuntu/x.h
0 0 2-31 * *       test $(date +\%u) -ne 7 && /home/ubuntu/y.h

$(date '+%u') returns 1-7 representing Monday thru Sunday. Try echo $(date '+%u') for an example.

How to instruct cron to execute a job every second week?

How about this, it does keep it in the crontab even if it isn't exactly defined in the first five fields:

0 6 * * Tue expr `date +\%W` \% 2 > /dev/null || /scripts/fortnightly.sh

Running a cron job at 2:30 AM everyday

crontab -e

add:

30 2 * * * /your/command

How do you schedule cron jobs for multiple dates?

If there is no common pattern, it is worth using three different lines:

0 0  7 12 * your_awesome_script
0 0 14  1 * your_awesome_script
0 0 21  2 * your_awesome_script

You could try to get a complex syntax taking advantage of the day of the week, etc, but it would get quite difficult to understand.

Remember the format:

 +---------------- minute (0 - 59)
 |  +------------- hour (0 - 23)
 |  |  +---------- day of month (1 - 31)
 |  |  |  +------- month (1 - 12)
 |  |  |  |  +---- day of week (0 - 6) (Sunday=0 or 7)
 |  |  |  |  |
 *  *  *  *  *  command to be executed

How do I schedule jobs in Jenkins?

By setting the schedule period to 15 13 * * * you tell Jenkins to schedule the build every day of every month of every year at the 15th minute of the 13th hour of the day.

Jenkins used a cron expression, and the different fields are:

1. MINUTES Minutes in one hour (0-59)
2. HOURS Hours in one day (0-23)
3. DAYMONTH Day in a month (1-31)
4. MONTH Month in a year (1-12)
5. DAYWEEK Day of the week (0-7) where 0 and 7 are sunday

If you want to schedule your build every 5 minutes, this will do the job : */5 * * * *

If you want to schedule your build every day at 8h00, this will do the job : 0 8 * * *

For the past few versions (2014), Jenkins have a new parameter, H (extract from the Jenkins code documentation):

To allow periodically scheduled tasks to produce even load on the system, the symbol H (for “hash”) should be used wherever possible.

For example, using 0 0 * * * for a dozen daily jobs will cause a large spike at midnight. In contrast, using H H * * * would still execute each job once a day, but not all at the same time, better using limited resources.

Note also that:

The H symbol can be thought of as a random value over a range, but it actually is a hash of the job name, not a random function, so that the value remains stable for any given project.

More example of using 'H'

Run CRON job everyday at specific time

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.

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