Wrong uptime without /proc

[polluks]

       _,met$$$$$gg.          xx@yy@ssh
    ,g$$$$$$$$$$$$$$$P.       ------------------------
  ,g$$P"        """Y$$.".     OS: Debian GNU/Linux 8 (jessie) x86_64
 ,$$P'              `$$$.     Kernel: 4.15.18-30-pve
',$$P       ,ggs.     `$$b:   Uptime: 19193 days, 10 hours, 11 mins
`d$$'     ,$P"'   .    $$$    Shell: bash 4.3.30
 $$P      d$'     ,    $$P    Terminal: /dev/pts/2
 $$:      $$.   -    ,d$$'    Memory: 0MiB / 0MiB
 $$;      Y$b._   _,d$P'
 Y$$.    `.`"Y$$$$P"'
 `$$b      "-.__
  `Y$$
   `Y$$.
     `$$b.
       `Y$$b.
          `"Y$b._
              `"""

By the way pfetch is smarter.