Hello,

 The Hurd version of uptime(1) (of w(1), actually) doesn't
work  with uptimes  larger than  2485 days,  12  hours, 19
minutes, 24 secondes (that is, larger than 214748364 which
is  2^31/10).  For  example,  it prints  6.-128 years  for
214748365 seconds, as you  can see using the attached file
(which works on GNU/Linux as well).

 This    is    due    to    an   integer    overflow    in
libshouldbeinlibc/timefmt.c:fmt_named_len()     at    line
130. The first check (num < 10) is not enough to see if we
have a "low number". 214748365  secondes gives a num of 7,
which is  less than 10, but will  overflow when multiplied
by 10.

 The overflow  can be  avoided by changing  the condition.
tv->tv_sec < LONG_MAX  sounds reasonable enough, as tv_sec
is  a long in  most OSes  (at least,  GNU/Linux, GNU/Hurd,
*BSD and  Solaris).  But POSIX defines  the `tv_sec' field
in  `struct timeval'  to be  a  time_t, which  can be  any
integer or  real type.  Someone suggested to  do something
like :

 if (tv->tv_sec  < (time_t)  pow (2, CHAR_BIT  * sizeof (time_t) - 1)
     && ...)

... but  that is  well, a  bit too much  (and adds  a libm
dependency for libshouldbeinlibc).

  Both  solutions have been  successfully tested  on three
different  systems.  Note that  uptime(1)  prints a  large
approximation of uptimes  in those cases, albeit seemingly
correct.