The doc string is very old.
https://github.com/JuliaLang/julia/commit/5e627b214c3601c5772530878b64693e7b66be15
And I'm not sure if it is accurate anymore. It is very likely platform
dependent. On Linux it's using clock_gettime(CLOCK_MONOTONIC) and I
didn't find anything that suggests it'll wrap around that fast on
64bits or 32bits.
"The time corresponding to 0 is undefined" also does not mean the
value followed by 1 is the max value. It is 0, just that it does not
represent any particular time, neither does any other values it
returns.
This function also does not give ns precision. So most likely it'll
never return 1
Finally, please stop posting to this list and use
https://discourse.julialang.org/ instead.