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

#include <iostream>
#include <string>
#include <limits>
#include <cassert>
#include <ctime>

template<typename T>
std::string tobits(T n, int d)
{
    assert(n > 0);
    assert((0 < d) && (d <= std::numeric_limits<T>::digits));

    std::string result;
    for(T i = static_cast<T>(1) << (d - 1); i > 0; i >>= 1)
    {
        result += ((n & i) != 0) ? "■" : "□";
    }
    return result;
}

int main(int, char* [])
{
    std::time_t raw;
    std::time(&raw);
    std::tm* t = std::localtime(&raw);

    std::cout << tobits(t->tm_hour, 6) << "\n"
              << tobits(t->tm_min,  6) << "\n"
              << tobits(t->tm_sec,  6) << "\n";

    return 0;
}