rubyで月の月初と月末の日付をつくる
require 'date'
day = Date.today
start_date = Date::new(day.year,day.month, 1)
end_date = start_date >> 1
end_date = end_date - 1
require 'date'
day = Date.today
start_date = Date::new(day.year,day.month, 1)
end_date = start_date >> 1
end_date = end_date - 1