29 Time library [time]

29.8 The civil calendar [time.cal]

29.8.17 Class year_month_weekday_last [time.cal.ymwdlast] Overview [time.cal.ymwdlast.overview]

namespace std::chrono { class year_month_weekday_last { chrono::year y_; // exposition only chrono::month m_; // exposition only chrono::weekday_last wdl_; // exposition only public: constexpr year_month_weekday_last(const chrono::year& y, const chrono::month& m, const chrono::weekday_last& wdl) noexcept; constexpr year_month_weekday_last& operator+=(const months& m) noexcept; constexpr year_month_weekday_last& operator-=(const months& m) noexcept; constexpr year_month_weekday_last& operator+=(const years& y) noexcept; constexpr year_month_weekday_last& operator-=(const years& y) noexcept; constexpr chrono::year year() const noexcept; constexpr chrono::month month() const noexcept; constexpr chrono::weekday weekday() const noexcept; constexpr chrono::weekday_last weekday_last() const noexcept; constexpr operator sys_days() const noexcept; constexpr explicit operator local_days() const noexcept; constexpr bool ok() const noexcept; }; }
year_month_weekday_last represents a specific year, month, and last weekday of the month.
year_month_weekday_last is a field-based time point with a resolution of days, except that it is restricted to pointing to the last weekday of a year and month.
[Note 1: 
year_month_weekday_last supports years- and months-oriented arithmetic, but not days-oriented arithmetic.
For the latter, there is a conversion to sys_days, which efficiently supports days-oriented arithmetic.
— end note]
year_month_weekday_last meets the Cpp17EqualityComparable (Table 28) requirements.
year_month_weekday_last is a trivially copyable and standard-layout class type.