chomado_year.cpp

#include <chrono>
#include <iostream>

// compile with -std=c++11 option 

int main(){
    typedef std::chrono::duration <int,std::ratio<24*60*60> > chomado_year;
    std::chrono::hours seven_days(24*7);
    std::cout << "7 days is " << std::chrono::duration_cast<chomado_year>(seven_days).count() << " years for chomado" << std::endl;
}

output

7 days is 7 years for chomado

http://cpplover.blogspot.jp/2012/05/c11_24.html
http://ja.cppreference.com/w/cpp/chrono/duration
を参考に初めてさわってみました。