[9fans] nsec limits?

[EBo]

I am setting up some timing tests and am currently dumping the 
timestamps using nsec().  When I post-process the data I find that the 
it is wrapping around, but I have not found anything that clearly states 
when it does that.  From the code I am guessing that is on the second 
boundary.  Is that correct?

  EBo --