#!/bin/sh

set -eu
u="Run the command 'ARG ...' on DAY.
DAY can be a 'case' pattern, like 'Mon|Wed|Thu'."
eval "$(args $0 day -r -u "$u" -- "$@")"

if $(eval "case \$(date +%a) in $day ) true ;; *) false ;; esac"); then
  exec "$@"
fi