I'm really curious about your use-case. Are you just looking to tweak the behavior of the VCS w.r.t. a timestamp-sensitive build system?

I will say that file timestamps invoke horrible, horrible memories of an employer that used Visual Source[un-]Safe -- a VCS that relied on accurate client system time for history integrity. I.e. the repo was easily corrupted if a client wasn't on synchronized time. Also, race conditions. AFAICT, it met none of the conditions casually denoted by the words "Version Control System".