The jobs are not shown on site when the job start date or the show until date are passed before and non of babysitter can see and apply for the job.  We changed this to only job expired date to show until date now.   If the job start date is passed, the jobs are shown and babysitter can check and apply the job until the show until date.
 
If the parent who post the job already choose and agree the job with a babysitter or the parent cancel the job before the show until date, the jobs are not shown on the site.