wday -> Integer[permalink][rdoc][edit]-
曜日を0(日曜日)から6(土曜日)の整数で返します。
p sun = Time.new(2017, 9, 17, 10, 34, 15, '+09:00') # => 2017-09-17 10:34:15 +0900 p sun.wday # => 0 p mon = Time.new(2017, 9, 18, 10, 34, 15, '+09:00') # => 2017-09-18 10:34:15 +0900 p mon.wday # => 1 p tue = Time.new(2017, 9, 19, 10, 34, 15, '+09:00') # => 2017-09-19 10:34:15 +0900 p tue.wday # => 2 p wed = Time.new(2017, 9, 20, 10, 34, 15, '+09:00') # => 2017-09-20 10:34:15 +0900 p wed.wday # => 3 p thu = Time.new(2017, 9, 21, 10, 34, 15, '+09:00') # => 2017-09-21 10:34:15 +0900 p thu.wday # => 4 p fri = Time.new(2017, 9, 22, 10, 34, 15, '+09:00') # => 2017-09-22 10:34:15 +0900 p fri.wday # => 5 p sat = Time.new(2017, 9, 23, 10, 34, 15, '+09:00') # => 2017-09-23 10:34:15 +0900 p sat.wday # => 6