$time=~s{
           #$1    $2    $3      $4    $5    $6     $7
           (\d+)/(\d+)/(\d+)\s+(\d+):(\d+):(\d+)\.(\d+)
          }
          {
           sprintf '%04d/%02d/%02d %02d:%02d:%02d.%3d',
                    $1,  $2,  $3,  $4,  $5,  $6,  $7
          }xe
      or die "Failed to normalize '$time'\n";