DouKaku?

#! c:\ruby\bin\ruby.exe -Ks

String.class_eval do |string|
    def words
        self.split(//)
    end
    def fix_width(width, padding)
        (self.words.size > width) ? self : (padding * (width - self.words.size) + self)
    end
end

Fixnum.class_eval do |fixnum|
    alias :to_s_orig :to_s
    def to_s(base, width)
        binary = self.to_s_orig(base).fix_width(width, "0")
    end
end

class BinaryClock
    attr_accessor :now
    def initialize
        self.now = Time.now
    end
    def print
        output(self.now.hour.to_s(2, 5))
        output(self.now.min.to_s(2, 6))
    end
private
    def output(binary)
        puts binary.words.map { |f| f == "0" ? "□" : "■" }.join.fix_width(6, "　")
    end
end

BinaryClock.new.print

{Time now print24. String streamContents: [:ss |
    (Time now print24 subStrings: ':')
        do: [:each | ss nextPutAll: (
            ((each asInteger radix: 2) forceTo: 7 paddingStartWith: $0)
                translateWith: ({$0 asciiValue + 1 -> $□. $1 asciiValue + 1 -> $■} as: Dictionary))]
        separatedBy: [ss space]]}

"=> #('22:50:58' '□□■□■■□ □■■□□■□ □■■■□■□') "