Me, DooCi and EPICFACE were playing a jump map on my server and after the time was over it went to negative times.
When I looked over at the time on the bottom right corner of the screen as soon as zero hit, it said N/A. (This applies to all of the negative times too)
[13:07:24] 0:01 left in match.
[13:07:25] 0.00 left in match.
[13:07:26] 0:-1 left in match.