All about Schedules :

Tables

#SCHCONFIG
This table contains all scheduled job entries.
scchost -the host name of the instance on which the scheduled job will be run
sccpathinfo-the command name
sccquery-query string for the scheduled command.

#SCHACTIVE
The list containing what job will need to be run and the time when the job should execute
schactive.scsjobnbr =schconfig.sccjobrefnum

#SCHSTATUS
This table is a log of the status of scheduled jobs
schstatus.scsjobnbr =schconfig.sccjobrefnum
scsstate:state of the scheduled job.
scsresult: result of job: success or fail.

#SCHERRORLOG
This table contains the exception information when a job fails to execute successfully.
#SCHORDERS
This table contains the entries for scheduled orders

#SCHBRDCST
This table is used to log the status of broadcast commands for each of the clones
schbrdcst.scsjobnbr =schconfig.sccjobrefnum

#SCHCMD
The URLsthat can be used as a scheduled job by a store. This is for the Scheduler menu in the Administration Console.
supporting tables:CHKARRANG/CHKCMD