suggest to use a different example rather then format method #22

The Date#format Method
class Date
  def format( spec ) self.strftime( spec.to_strftime ); end
end
The new Date#format method formats the date like the passed in example:

date = Date.today   ## test run on 2020-02-09

p date.format( 'January 02, 2006' )         #=> "February 09, 2020"

↪  irb                                                                                                                                                Fri Feb 21 12:03:54 CST 2020
irb 0.9.6(09/06/30) for ruby-2.5.1 [ x86_64-darwin16 ]
using config {:auto_completion=>"on", :auto_indent=>"on", :prompt_mode=>:DEFAULT, :use_bond=>"off"}, type "conf" to display configuration, type "exit" to quit current session
current context: main(Object)#70113110176120
irb(main):001:0> require 'date'
=> true
irb(main):002:0> date = Date.today
=> #<Date: 2020-02-21 ((2458901j,0s,0n),+0s,2299161j)>
irb(main):003:0> date.format
Traceback (most recent call last):
        2: from /Users/rain/.rvm/rubies/ruby-2.5.1/bin/irb:11:in `<main>'
        1: from (irb):3
NoMethodError (private method `format' called for #<Date: 2020-02-21 ((2458901j,0s,0n),+0s,2299161j)>)
irb(main):004:0>

class Date
  def format_as( spec ) self.strftime( spec.to_strftime ); end
end

date = Date.today   ## test run on 2020-02-09

p date.format_as( 'January 02, 2006' )         #=> "February 09, 2020"