Edit Jobs:
You may edit a job listing at anytime through the "My Jobs" category. Jobs that are edited are still displayed for the original 4 months. The posting clock is not re-started. To restart the posting clock, you need to "Duplicate" or "Renew" the job. A "Duplicate" or "Renewed" job counts against your total allowed job postings.
There is also a "Multi Renew" function to make renewing multiple jobs easy.