Scheduling jobs using Cron

Cron 

Cron is the general name of the tool that runs scheduled jobs consisting of shell commands
or shell scripts.
Crond is the service that interprets “crontab files” every minute and submits
the corresponding jobs to cron at scheduled times.
A crontab, short for “cron table,” is a file containing jobs and schedule data.
Crontab is also a command that invokes a text editor to allow you to edit a crontab
file.

Job scheduling using Crontab

The five time-and-date fields cannot contain spaces. The five time-and-date fields and their allowed values are as follows:

minute (0-59)

hour(0-23, 0 = midnight)

day (1-31)

month (1-12)

weekday (0-6, 0 = Sunday)