std::chrono::weekday::weekday

 

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Date and time library

Time point time_point (C++11) clock_time_conversion (C++20)   clock_cast (C++20) Duration duration (C++11) Clocks system_clock (C++11) steady_clock (C++11) is_clock (C++20) utc_clock (C++20) tai_clock (C++20) high_resolution_clock (C++11) gps_clock (C++20) file_clock (C++20) local_t (C++20) Time of day is_amis_pm (C++20)(C++20) make12make24 (C++20)(C++20) hh_mm_ss (C++20)

Calendar day (C++20) month (C++20) year (C++20) weekday (C++20) operator/ (C++20) year_month_day (C++20) year_month_day_last (C++20) year_month_weekday (C++20) year_month_weekday_last (C++20)   weekday_indexed (C++20) weekday_last (C++20) month_day (C++20) month_day_last (C++20) month_weekday (C++20) month_weekday_last (C++20) year_month (C++20) last_speclast (C++20)(C++20) chrono I/O parse (C++20)

Time zone tzdb (C++20) tzdb_list (C++20) get_tzdbget_tzdb_listreload_tzdbremote_version (C++20)(C++20)(C++20)(C++20) sys_info (C++20) local_info (C++20) nonexistent_local_time (C++20) ambiguous_local_time (C++20) locate_zone (C++20) current_zone (C++20) time_zone (C++20) choose (C++20) zoned_traits (C++20) zoned_time (C++20) time_zone_link (C++20) leap_second (C++20) leap_second_info (C++20) get_leap_second_info (C++20) C-style date and time

 

std::chrono::weekday

Member functions

weekday::weekday

weekday::operator++weekday::operator--

weekday::operator+=weekday::operator-=

weekday::c_encodingweekday::iso_encoding

weekday::ok

weekday::operator[]

Nonmember functions

operator==

operator+operator-

operator<<

from_stream

Helper classes

formatter<std::chrono::weekday>

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

 

weekday() = default;	(1)	(since C++20)
constexpr explicit weekday( unsigned wd ) noexcept;	(2)	(since C++20)
constexpr weekday( const std::chrono::sys_days& sd ) noexcept;	(3)	(since C++20)
constexpr explicit weekday( const std::chrono::local_days& ld ) noexcept;	(4)	(since C++20)

Constructs a weekday object.

1) Default constructor leaves the weekday value uninitialized.

2) Constructs a weekday object holding the weekday value wd. If wd == 7, the value held is 0. If wd > 255, the value held is unspecified.

3) Constructs a weekday object representing the day of the week sd corresponds to. This constructor defines an implicit conversion from std::chrono::sys_days to weekday.

4) Constructs a weekday object representing the day of the week ld corresponds to, as if by weekday(std::chrono::sys_days(ld.time_since_epoch())).

Parameters

wd	-	a weekday value
sd	-	a system days object
ld	-	a local days object

Example

Run this code

#include <chrono>
#include <iomanip>
#include <iostream>

int main()
{
    constexpr std::chrono::weekday friday{5}; // uses overload (2)
    static_assert(friday == std::chrono::Friday);

    for (int y{2020}; y <= 2024; ++y)
    {
        const std::chrono::year cur_year{y};
        for (int cur_month{1}; cur_month != 13; ++cur_month)
        {
            const std::chrono::year_month_day ymd{cur_year/cur_month/13};
            const std::chrono::weekday cur_weekday{std::chrono::sys_days(ymd)}; // (3)
            if (cur_weekday == friday)
                std::cout << ymd << " is " << friday << '\n';
        }
    }
}

Output:

2020-03-13 is Fri
2020-11-13 is Fri
2021-08-13 is Fri
2022-05-13 is Fri
2023-01-13 is Fri
2023-10-13 is Fri
2024-09-13 is Fri
2024-12-13 is Fri