open UP, "< /proc/uptime"
    or  die "Can't read /proc/uptime: $!$/";
my @boot= ( localtime
    time() - ( split ' ', <UP> )[0]
)[ reverse 0..5 ];
close UP;
$boot[0] += 1900;
$boot[1]++;
$_= sprintf "%02d", $_   for  @boot;
my $boot= join( '-', @boot[0..2] )
    . '/' . join( ':', @boot[3..5] );
print "Last booted $boot$/";