I enjoyed Vinge's future history: > Take the Traders' method of timekeeping. The frame corrections were incredibly complex - and down at the very bottom of it

I enjoyed Vinge's future history: > Take the Traders' method of timekeeping. The frame corrections were incredibly complex - and down at the very bottom of it was a little program that ran a counter. Second by second, the Qeng Ho counted from the instant that a human had first set foot on Old Earth's moon. But if you looked at it still more closely ... the starting instant was actually about fifteen million seconds later, the 0-second of one of Humankind's first computer operating systems.