> In what version?

Solaris 8+ has support for locales. See man strftime(3C). However, it does
appear that the "w" command is not localized. Sorry about that:

kent@nomad-70:69> setenv LC_TIME fr
kent@nomad-70:70> date
vendredi, 30 septembre 2005, 20:07:46 PDT
kent@nomad-70:71> w |head -10
  8:07pm  up 24 day(s),  8:20,  4 users,  load average: 0.56, 0.38, 0.33
User     tty           login@  idle   JCPU   PCPU  what
kent     dtlocal      17Sep05    21   1:12     11  olwmslave
kent     pts/4        17Sep05 2days      6         /bin/csh
kent     pts/5        17Sep05    10      1      1  /bin/csh
kent     pts/6        17Sep05 2days                /bin/csh
kent     pts/7        17Sep0513days                /bin/csh
kent     pts/8        17Sep0511days                /bin/csh
kent     pts/9        17Sep05 8days                /bin/csh
kent     pts/10       17Sep05 4days                /bin/csh
kent@nomad-70:72> ...


Kent