#include <boost/date_time/gregorian/gregorian.hpp>
#include <boost/format.hpp>

using namespace boost::gregorian;

int getMonthWeek(const date& d)     //here sunday is first week day
{
    auto getYearWeek = [](const date& d){return d.week_number()+(d.day_of_week()==Sunday?1:0);};
    return getYearWeek(d) - getYearWeek(date{d.year(), d.month(), 1});
}

int main() {
    const int days_per_week = 7;
    const int months_per_year = 12;
    const int weeks_per_block = 6;
    const int months_per_block = 3;
    const int blocks_per_year = ceil( double( months_per_year ) / months_per_block );
    const greg_year year = 2015;

    for(auto yearblock = 0; yearblock != blocks_per_year; yearblock++) {
        int monthweek2blockmonth2weekday2monthday [weeks_per_block] [months_per_block] [days_per_week] = {};

        for(auto blockmonth = 0; blockmonth != months_per_block; blockmonth++) {
            const int yearmonth = yearblock * months_per_block + blockmonth;

            if(yearmonth < months_per_year) {
                const greg_month gregmonth = yearmonth + 1;

                std::cout << boost::str(boost::format("%|=22|") % gregmonth.as_long_string());

                for(date d{ year, gregmonth, 1 }, d_last = d.end_of_month(); d <= d_last; d += date_duration(1))
                    monthweek2blockmonth2weekday2monthday [getMonthWeek(d)] [blockmonth] [d.day_of_week()] = d.day();
            }
        }
        std::cout << std::endl;

        for(const auto& blockmonth2weekday2monthday: monthweek2blockmonth2weekday2monthday) {
            for(const auto& weekday2monthday: blockmonth2weekday2monthday) {
                for(const auto& monthday: weekday2monthday)
                    std::cout << ( monthday ? boost::str(boost::format("%|3|") % monthday) : "   " );
                std::cout << " ";
            }
            std::cout << std::endl;
        }
    }
}