You will be interested in these 2 fields in each Job:
1, Job's Expiration Date: This field will get from the package (if you use the package), otherwise it will be taken here (Jobmonster -> Settings -> Job tab) http://prntscr.com/r0kqj5
This field can only be changed by the admin. Jobs will no longer be displayed when this field is exceeded.
2, Close date field:
Time that candidates can apply for job. When this time is exceeded, the job will display the "Job Exprired" icon and can't apply job. Employer can change this value.
http://prntscr.com/r0kvy7
http://prntscr.com/r0kw3s
Best regards.