# std::chrono::year_month_day::year_month_day

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< cpp‎ | chrono‎ | year month day

year_month_day() = default; | (1) | (since C++20)
constexpr year_month_day(const std::chrono::year& y, const std::chrono::month& m, const std::chrono::day& d) noexcept; | (2) | (since C++20)
constexpr year_month_day(const std::chrono::year_month_day_last& ymdl) noexcept; |  | (since C++20)
constexpr year_month_day(const std::chrono::sys_days& dp) noexcept; |  | (since C++20)
explicit constexpr year_month_day(const std::chrono::local_days& dp) noexcept; |  | (since C++20)

Constructs a `year_month_day` object.

1) Default constructor leaves the date uninitialized.
2) Constructs a `year_month_day` object that stores the year `y`, month `m` and day `d`.
3) Constructs a `year_month_day` object that stores the year ymdl.year(), month ymdl.month() and day ymdl.day().
4) Constructs a `year_month_day` object that represent the same date as the one represented by `dp`.
5) Constructs a `year_month_day` object that represent the same date as the one represented by `dp`, as if by year_month_day(sys_days(dp.time_since_epoch())).

Constructors (3-4) define implicit conversions from std::chrono::year_month_day_last and std::chrono::sys_days, respectively.

For any `year_month_day` object `ymd` representing a valid date (ymd.ok() == true), converting `ymd` to `sys_days` and back yields the same value.

### Notes

A `year_month_day` can also be created by combining one of the partial-date types std::chrono::year_month and std::chrono::month_day with the missing component (day and year, respectively) using `operator/`.

### See also

operator/ (C++20) | conventional syntax for Gregorian calendar date creation (function)

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