grin-and-beer-it.rb

require 'csv'

ORDERING_FREQUENCY = ['Monday', 'Thursday', 'Wednesday']
def date_of_next(day, anchor)
  anchor + 0.upto(6).find {|i| Date::DAYNAMES[(anchor + i).wday] == day }
end

people = CSV.parse(File.read(ARGV[0])).shuffle
start = Date.parse(ARGV[1]) rescue Date.today
schedule = ORDERING_FREQUENCY.cycle.take(30).map {|day| start = date_of_next(day, start) }
puts schedule.each_with_object(Array.new).with_index {|(date, arr), i| 
  arr << [date.to_s, people[i % people.length]].join(',') 
}.join("\n")