If you want to schedule your Jenkins Job periodically, then you need to Configure your job in the "Build Periodically" checkbox, and in the Schedule, text field add your requirement. You can see the syntax below.
Jenkins used corn expression, and the different fields are:
MINUTES Minutes in one hour (0-59)
HOURS Hours in one day (0-23)
DAY MONTH Day in a month (1-31)
MONTH Month in a year (1-12)
DAY WEEK 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 * * * *