std::chrono::year_month_day

 

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C-style date and time

 

std::chrono::year_month_day

Member functions

year_month_day::year_month_day

year_month_day::operator+=year_month_day::operator-=

year_month_day::yearyear_month_day::monthyear_month_day::day

year_month_day::operator sys_daysyear_month_day::operator local_days

year_month_day::ok

Nonmember functions

operator==operator<=>

operator+operator-

operator<<

from_stream

Helper classes

formatter<std::chrono::year_month_day>

hash<std::chrono::year_month_day> (C++26)

 

Defined in header <chrono>
class year_month_day;		(since C++20)

The class year_month_day represents a specific year, month, and day. It is a field-based time point, with a resolution of std::chrono::days. std::chrono::years- and std::chrono::months-oriented arithmetic are supported directly. An implicit conversion to and from std::chrono::sys_days allows std::chrono::days-oriented arithmetic to be performed efficiently.

year_month_day is a TriviallyCopyable StandardLayoutType.

Member functions

(constructor)	constructs a year_month_day (public member function)
operator+=operator-=	modifies the time point by some number of months or years (public member function)
yearmonthday	accesses the year, month, and day stored in this object (public member function)
operator sys_daysoperator local_days	converts to a std::chrono::time_point (public member function)
ok	checks if the year_month_day represents a valid date (public member function)

Nonmember functions

operator==operator<=> (C++20)	compares two year_month_day values (function)
operator+operator- (C++20)	adds or subtracts a year_month_day and some number of years or months (function)
operator<< (C++20)	outputs a year_month_day into a stream (function template)
from_stream (C++20)	parses a year_month_day from a stream according to the provided format (function template)

Helper classes

std::formatter<std::chrono::year_month_day> (C++20)	formatting support for year_month_day (class template specialization)
std::hash<std::chrono::year_month_day> (C++26)	hash support for std::chrono::year_month_day (class template specialization)

Example

Run this code

#include <chrono>
#include <iostream>
 
int main()
{
    const std::chrono::time_point now{std::chrono::system_clock::now()};
 
    const std::chrono::year_month_day ymd{std::chrono::floor<std::chrono::days>(now)};
 
    std::cout << "Current Year: " << static_cast<int>(ymd.year()) << ", "
                 "Month: " << static_cast<unsigned>(ymd.month()) << ", "
                 "Day: " << static_cast<unsigned>(ymd.day()) << "\n"
                 "ymd: " << ymd << '\n';
}

Possible output:

Current Year: 2023, Month: 9, Day: 4
ymd: 2023-09-04