#include <chrono>
 #include <iostream>

 int main(){

   std::cout << std::fixed  std::endl;

   auto timeNow= std::chrono::system_clock::now();
   auto duration= timeNow.time_since_epoch();

   std::cout << "time since 1.1.1970:" << std::endl;
   std::cout << std::endl;

   std::cout << duration.count() << " nanoseconds" << std::endl;

   typedef std::chrono::duration<double> MySecondTick;
   MySecondTick mySecond(duration);
   std::cout << mySecond.count() << " seconds" << std::endl;

   const int minute= 60;
   typedef std::chrono::duration<double, std::ratio<minute>> MyMinuteTick;
   MyMinuteTick myMinute(duration);
   std::cout << myMinute.count() << " minutes" << std::endl;

   const int hour= minute * 60;
   typedef std::chrono::duration<double, std::ratio<hour>> MyHourTick;
   MyHourTick myHour(duration);
   std::cout << myHour.count() << " hours" << std::endl;

   const int day= hour * 24;
   typedef std::chrono::duration<double, std::ratio<day>> MyDayTick;
   MyDayTick myDay(duration);
   std::cout << myDay.count() << " days" << std::endl;

   const int month= day * 30;
   typedef std::chrono::duration<double, std::ratio<month>> MyMonthTick;
   MyMonthTick myMonth(duration);
   std::cout << myMonth.count() << " months" << std::endl;

   const int year= month * 12;
   typedef std::chrono::duration<double, std::ratio<year>> MyYearTick;
   MyYearTick myYear(duration);
   std::cout << myYear.count() << " years" << std::endl;

   typedef std::chrono::duration<double, std::ratio<3600>> MyHourTick;
   MyHourTick myOneHour(duration);
   std::cout << myOneHour.count() << " hours" << std::endl;

   typedef std::chrono::duration<double, std::ratio<2700>> MyLessonTick;
   MyLessonTick myLesson(duration);
   std::cout << myLesson.count() << " lessons" << std::endl;

   std::cout << std::endl;

 }