My subject matter expertise is NOT technical so if this has to do with any service you are receiving from CircaWorks, please ask the question again if necessary. I don't know why your new ATS representative has made this recommendation, and were you a client I would challenge that. H/she may know their system, but from an audit standpoint, I would disagree with this recommendation. So, I will give you some important substantive analytical suggestions that you should at least discuss with your new rep. FIRST, I strongly suggest that you make the transition coincide with the anniversary date of your AAP. In other words, if your AAP year is a calendar year, I would not put ANY data from your old system on the new system EXCEPT for vacancies that you won't/do not expect to fill until AFTER January 1. In my experience, mixing systems and data from one system to another is a complication you don't need in a compliance review! If your AAP Year is OTHER THAN a Calendar Year, I would consider putting NEW openings as of January 1 on the new system and, if at all possible, continue to use the old ATS until Dec 31. Then pull from whichever system you need the data for the actual months of your AAP Year. REMEMBER, irrespective of changing ATS systems, for analysis purposes it is the ALWAYS the date you MAKE THE SELECTION DECISION that is the operative date, NOT the posting date!!! And you ALWAYS ALWAYS want ONLY the applicants that are associated with the DECISION data -- no matter in which AAP Year they applied!!! The objective is to "match" ALL -- BUT ONLY-- the Internet Applicants who were considered for each one of the SELECTION made in the 12 months of the APP Year. These systems may be called "APPLICANT" tracking, but the OFCCP is concerned with unlawful DENIAL of an opportunity and that does not occur until the job offer is made -- by the way, irrespective of whether the individual accepts the offer. If s/he turns the job down, you have still SELECTED, which is why hire date -- altho' commonly used -- is incorrect and irrelevant (unless that's all your system will track). That's a payroll consequence of granting an opportunity and is often as much a result of the decision by the new hire not by the employer, right? And the applicants who were not selected were denied the opportunity even before the selectee starts to work, also right? No matter what your AAP year is, I strongly urge that when you migrate your applicant data, migrate ONLY the applicants for positions for which you have NOT YET MADE A SELECTION. Whether you need to pull data from one system or two, when you do the selection analysis for a particular AAP Year, operate off the date the requisition was filled NOT the date of posting or application. Good luck with the transitioning!