function cur_weekday {
  typeset ymd=$1 ym y m d i
  (( ymd >= 17520914 && ymd <= 17520930 )) && (( ymd = ymd - 11 ))
  ((  d = ymd % 100 ))
  (( ym = ymd / 100 ))
  ((  y = ym  / 100 ))
  ((  m = ym  % 100 ))
  cal $m $y | while read i; do
    set -- $i
    [[ $1 == 1 ]] && { 
      printf "%s\n" $(( ( 13 + d - $# ) % 7 ))
      break
    }
  done
}