Show the possible tokens of Ruby Time#strftime

ruby-srtftime

#!/usr/bin/env ruby

# one line version:
# t = Time.new; puts (65.upto(90).map{|i|s = "%%#{i.chr}: %#{i.chr}"; t.strftime(s).ljust(25) + t.strftime(s.downcase)}.join("\n"))

# Output:
#
#  %A:   Tuesday            %a:   Tue
#  %B:   September          %b:   Sep
#  %C:   20                 %c:   Tue Sep 21 08:53:35 2010
#  %D:   09/21/10           %d:   21
#                           %e:   21
#  %F:   2010-09-21       
#  %G:   2010               %g:   10
#  %H:   08                 %h:   Sep
#  %I:   08               
#                           %j:   264
#                           %k:    8
#  %L:   103                %l:    8
#  %M:   53                 %m:   09
#  %N:   103078000          %n:   \n (newline)
#                         
#  %P:   am                 %p:   AM
#                         
#  %R:   08:53              %r:   08:53:35 AM
#  %S:   35                 %s:   1285052015
#  %T:   08:53:35           %t:   
#  %U:   38                 %u:   2
#  %V:   38                 %v:   21-SEP-2010
#  %W:   38                 %w:   2
#  %X:   08:53:35           %x:   09/21/10
#  %Y:   2010               %y:   10
#  %Z:   CEST               %z:   +0200


t = Time.new

result = 'A'.ord.upto('Z'.ord).map do |i|
  str = "%#{i.chr}"
  strf = t.strftime(str)
  str_d = str.downcase
  strf_d = t.strftime(str_d).sub("\n", "\\n (newline)")
  (str == strf ? '' : "  #{str}: #{strf}").ljust(25) +
  (str_d == strf_d ? '' : "  #{str_d}: #{strf_d}")
end.join("\n")

puts "\n" + result + "\n\n"