Did CVS make the timestamp in the history at the server?
Timestamps from CVS histories are not very reliable - CVS made them on the client side rather than at the server
https://gitlab.com/esr/cvs-fast-export/-/blob/1.66/revcvs.c?ref_type=tags#L228-231
this can happen is that CVS timestamps commits on the client, not at the server
Is this a real story?
I checked r1.1 of commit.c of cvs, it seems cvs commit is done with ci(1) on the server.
http://cvs.savannah.gnu.org/viewvc/cvs/ccvs/src/commit.c?revision=1.1&view=markup#l248
I suppose that the time stamp skews had been happened when the time on the cvs server was wrong.