Scheduling 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 uses a cron expression, and the different fields are:
MINUTES Minutes in one hour (0-59)
HOURS Hours in one day (0-23)
DAYMONTH Day in a month (1-31)
MONTH Month in a year (1-12)
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 has a new parameter, H (extract from the Jenkins code documentation):
To allow periodically scheduled tasks to produce an 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.