std::chrono::year_month_day_last::operatorsys_days,(3)

NAME
std::chrono::year_month_day_last::operatorsys_days, - std::chrono::year_month_day_last::operatorsys_days,

Synopsis
   constexpr operator std::chrono::sys_days() const noexcept; (1) (since C++20)
   constexpr explicit operator std::chrono::local_days() const (2) (since C++20)
   noexcept;
   Converts *this to a std::chrono::time_point representing the same date as this
   year_month_day_last. This is equivalent to composing a year_month_day from year(),
   month() and day() and converting that year_month_day to the destination type.
   1) Equivalent to std::chrono::sys_days(year()/month()/day()).
   2) Equivalent to std::chrono::local_days(year()/month()/day()).

Example
// Run this code
 #include <array>
 #include <chrono>
 #include <iostream>
 #include <string_view>
 using namespace std::chrono;
 using namespace std::literals;
 int main()
 {
     constexpr std::chrono::year y{2023y};
     constexpr std::array quarters{"1st"sv, "2nd"sv, "3rd"sv, "4th"sv};
     constexpr auto mq{12 / 4}; // months per quarter
     std::cout << "In year " << static_cast<int>(y) << '\n';
     for (auto q = 1; q < 5; ++q)
     {
         const auto ls = y / std::chrono::month(q * mq) / Sunday[last];
         const auto ld = y / std::chrono::month(q * mq) / last;
         // subtract last Sunday from last day for day of week
         const auto index = (sys_days(ld) - sys_days(ls)).count();
         std::cout << "The " << quarters[q - 1] << " quarter ends on a "
                   << std::chrono::weekday(index) << '\n';
     }
 }

Output:
 In year 2023
 The 1st quarter ends on a Fri
 The 2nd quarter ends on a Fri
 The 3rd quarter ends on a Sat
 The 4th quarter ends on a Sun

See also
   operator sys_days converts to a std::chrono::time_point
   operator local_days (public member function of std::chrono::year_month_day)