A recent issue I was looking at confused me as we were adding SQL Agent Jobs to run a SSRS report but the agent job was not appearing in the ‘sysjobschedules’ table, eventually the job did appear but why did it not appear straight away.

The reason is the the sysjobschedules table refreshes every 20 minutes, which may affect the values returned by the sp_help_jobschedule stored procedure.

Read the article here on MSDN