Markus Kuhn writes:
we are just trying to define a robust interface to the clock information available to a good operating system
Most modern processors provide exact cycle counts. A good clock routine can combine cycle-count information with occasional TAI/UTC inputs to provide reasonably accurate local-time displays with extremely accurate time differences. The available resolution is going to drop below 1ns in a few years, so limiting yourself to 1ns seems rather shortsighted. (Yes, Virginia, you really can tell the difference on a Pentium 233 between something that takes 130ns and something that takes 135ns.)
external picosecond hardware phase comparators clocked by caesium time normals, which send you the data as ASCII floating point numbers
Why not settle on a 16-byte format that works for everything? If you're desperate to save space, you can truncate TAI64NA at the precision you need---8 bytes for TAI64 or 12 bytes for TAI64N. ---Dan 1000 recipients, 28.8 modem, 10 seconds. http://pobox.com/~djb/qmail/mini.html