Re: timestamp resolution

[Hans Aberg]

There is a document about JD, as well other time scales, at
  http://www.ucolick.org/~sla/leapsecs/timescales.html

Apparently, JD does not take into account leap seconds (see quote  
below), which makes it suitable for use in distributed computer  
systems. If one does not like the high numbers of JD (although in 64- 
bit, JD seconds would be able to count more that ten times of that  
the currently modeled universe age), there is a MJD = JD - 2400000.5.

It does not really make sense to discuss second or smaller divisions  
of time scales, unless one can handle the leap second question  
properly. So while at it, perhaps this question should be settled as  
well. :-)

  Hans Aberg


Quote from link above:

It should also be noted that the use of JD or MJD for the UTC time  
scale is problematic and ambiguous at the precision of one second. JD  
and MJD express the elapsed count of some form of ``day'' as real  
numbers along a presumably unsegmented, continuous number line. The  
UTC time scale (and, historically, GMT as used in practical  
situations before the advent of UTC) contains changes in rate and  
discontinuities. In particular, there is no obvious way to represent  
a leap second of UTC (or the smaller leaps present in the available  
forms of GMT and UTC before 1972) using JD or MJD notation.