# std::chrono::operator/ (calendar)

From cppreference.com
< cpp‎ | chrono

Defined in header `<chrono>` |  |
`year_month` |  |
constexpr auto operator/( const std::chrono::year& y, const std::chrono::month& m ) noexcept -> std::chrono::year_month; | (1) | (since C++20)
constexpr auto operator/( const std::chrono::year& y, int m ) noexcept -> std::chrono::year_month; | (2) | (since C++20)
`month_day` |  |
constexpr auto operator/( const std::chrono::month& m, const std::chrono::day& d ) noexcept -> std::chrono::month_day; | (3) | (since C++20)
constexpr auto operator/( const std::chrono::month& m, int d ) noexcept -> std::chrono::month_day; | (4) | (since C++20)
constexpr auto operator/( int m, const std::chrono::day& d ) noexcept -> std::chrono::month_day; | (5) | (since C++20)
constexpr auto operator/( const std::chrono::day& d, const std::chrono::month& m ) noexcept -> std::chrono::month_day; | (6) | (since C++20)
constexpr auto operator/( const std::chrono::day& d, int m ) noexcept -> std::chrono::month_day; | (7) | (since C++20)
`month_day_last` |  |
constexpr auto operator/( const std::chrono::month& m, std::chrono::last_spec ) noexcept -> std::chrono::month_day_last; | (8) | (since C++20)
constexpr auto operator/( int m, std::chrono::last_spec ) noexcept -> std::chrono::month_day_last; | (9) | (since C++20)
constexpr auto operator/( std::chrono::last_spec, const std::chrono::month& m ) noexcept -> std::chrono::month_day_last; | (10) | (since C++20)
constexpr auto operator/( std::chrono::last_spec, int m ) noexcept -> std::chrono::month_day_last; | (11) | (since C++20)
`month_weekday` |  |
constexpr auto operator/( const std::chrono::month& m, const std::chrono::weekday_indexed& wdi ) noexcept -> std::chrono::month_weekday; | (12) | (since C++20)
constexpr auto operator/( int m, const std::chrono::weekday_indexed& wdi ) noexcept -> std::chrono::month_weekday; | (13) | (since C++20)
constexpr auto operator/( const std::chrono::weekday_indexed& wdi, const std::chrono::month& m ) noexcept -> std::chrono::month_weekday; | (14) | (since C++20)
constexpr auto operator/( const std::chrono::weekday_indexed& wdi, int m ) noexcept -> std::chrono::month_weekday; | (15) | (since C++20)
`month_weekday_last` |  |
constexpr auto operator/( const std::chrono::month& m, const std::chrono::weekday_last& wdl ) noexcept -> std::chrono::month_weekday_last; | (16) | (since C++20)
constexpr auto operator/( int m, const std::chrono::weekday_last& wdl ) noexcept -> std::chrono::month_weekday_last; | (17) | (since C++20)
constexpr auto operator/( const std::chrono::weekday_last& wdl, const std::chrono::month& m ) noexcept -> std::chrono::month_weekday_last; | (18) | (since C++20)
constexpr auto operator/( const std::chrono::weekday_last& wdl, int m ) noexcept -> std::chrono::month_weekday_last; | (19) | (since C++20)
`year_month_day` |  |
constexpr auto operator/( const std::chrono::year_month& ym, const std::chrono::day& d ) noexcept -> std::chrono::year_month_day; | (20) | (since C++20)
constexpr auto operator/( const std::chrono::year_month& ym, int d ) noexcept -> std::chrono::year_month_day; | (21) | (since C++20)
constexpr auto operator/( const std::chrono::year& y, const std::chrono::month_day& md ) noexcept -> std::chrono::year_month_day; | (22) | (since C++20)
constexpr auto operator/( int y, const std::chrono::month_day& md ) noexcept -> std::chrono::year_month_day; | (23) | (since C++20)
constexpr auto operator/( const std::chrono::month_day& md, const std::chrono::year& y ) noexcept -> std::chrono::year_month_day; | (24) | (since C++20)
constexpr auto operator/( const std::chrono::month_day& md, int y ) noexcept -> std::chrono::year_month_day; | (25) | (since C++20)
`year_month_day_last` |  |
constexpr auto operator/( const std::chrono::year_month& ym, std::chrono::last_spec ) noexcept -> std::chrono::year_month_day_last; | (26) | (since C++20)
constexpr auto operator/( const std::chrono::year& y, const std::chrono::month_day_last& mdl ) noexcept -> std::chrono::year_month_day_last; | (27) | (since C++20)
constexpr auto operator/( int y, const std::chrono::month_day_last& mdl ) noexcept -> std::chrono::year_month_day_last; | (28) | (since C++20)
constexpr auto operator/( const std::chrono::month_day_last& mdl, const std::chrono::year& y ) noexcept -> std::chrono::year_month_day_last; | (29) | (since C++20)
constexpr auto operator/( const std::chrono::month_day_last& mdl, int y ) noexcept -> std::chrono::year_month_day_last; | (30) | (since C++20)
`year_month_weekday` |  |
constexpr auto operator/( const std::chrono::year_month& ym, const std::chrono::weekday_indexed& wdi ) noexcept -> std::chrono::year_month_weekday; | (31) | (since C++20)
constexpr auto operator/( const std::chrono::year& y, const std::chrono::month_weekday& mwd ) noexcept -> std::chrono::year_month_weekday; | (32) | (since C++20)
constexpr auto operator/( int y, const std::chrono::month_weekday& mwd ) noexcept -> std::chrono::year_month_weekday; | (33) | (since C++20)
constexpr auto operator/( const std::chrono::month_weekday& mwd, const std::chrono::year& y ) noexcept -> std::chrono::year_month_weekday; | (34) | (since C++20)
constexpr auto operator/( const std::chrono::month_weekday& mwd, int y ) noexcept -> std::chrono::year_month_weekday; | (35) | (since C++20)
`year_month_weekday_last` |  |
constexpr auto operator/( const std::chrono::year_month& ym, const std::chrono::weekday_last& wdl ) noexcept -> std::chrono::year_month_weekday_last; | (36) | (since C++20)
constexpr auto operator/( const std::chrono::year& y, const std::chrono::month_weekday_last& mwdl ) noexcept -> std::chrono::year_month_weekday_last; | (37) | (since C++20)
constexpr auto operator/( int y, const std::chrono::month_weekday_last& mwdl ) noexcept -> std::chrono::year_month_weekday_last; | (38) | (since C++20)
constexpr auto operator/( const std::chrono::month_weekday_last& mwdl, const std::chrono::year& y ) noexcept -> std::chrono::year_month_weekday_last; | (39) | (since C++20)
constexpr auto operator/( const std::chrono::month_weekday_last& mwdl, int y ) noexcept -> std::chrono::year_month_weekday_last; | (40) | (since C++20)

These operator/ overloads provide a conventional syntax for the creation of Gregorian calendar dates.

For creation of a full date, any of the following three orders are accepted:

- `year/month/day`
- `month/day/year`
- `day/month/year`.

In each case `day` can replaced with one of:

- std::chrono::last, for the last day of the month;
- `weekday[i]`, for the i-th weekday of the month;
- `weekday[std::chrono::last]`, for the last weekday of the month.

A plain integer is accepted if its meaning is unambiguous from the types of other operands: 2005y/4/5 is allowed, but 5/April/2005 is not.

Partial-date types (`year_month`, `month_day`, etc.) can be created by not applying the second operator/ in any of the three orders.

### Return value

1) std::chrono::year_month(y, m)
2) std::chrono::year_month(y, std::chrono::month(m))
3,6) std::chrono::month_day(m, d)
4) std::chrono::month_day(m, std::chrono::day(d))
5,7) std::chrono::month_day(std::chrono::month(m), d)
8,10) std::chrono::month_day_last(m)
9,11) std::chrono::month_day_last(std::chrono::month(m))
12,14) std::chrono::month_weekday(m, wdi)
13,15) std::chrono::month_weekday(std::chrono::month(m), wdi)
16,18) std::chrono::month_weekday_last(m, wdl)
17,19) std::chrono::month_weekday_last(std::chrono::month(m), wdl)
20) std::chrono::year_month_day(ym.year(), ym.month(), d)
21) std::chrono::year_month_day(ym.year(), ym.month(), std::chrono::day(d))
22,24) std::chrono::year_month_day(y, md.month(), md.day())
23,25) std::chrono::year_month_day(std::chrono::year(y), md.month(), md.day())
26) std::chrono::year_month_day_last(ym.year(), std::chrono::month_day_last(ym.month()))
27,29) std::chrono::year_month_day_last(y, mdl)
28,30) std::chrono::year_month_day_last(std::chrono::year(y), mdl)
31) std::chrono::year_month_weekday(ym.year(), ym.month(), wdi)
32,34) std::chrono::year_month_weekday(y, mwd.month(), mwd.weekday_indexed())
33,35) std::chrono::year_month_weekday(std::chrono::year(y), mwd.month(), mwd.weekday_indexed())
36) std::chrono::year_month_weekday_last(ym.year(), ym.month(), wdl)
37,39) std::chrono::year_month_weekday_last(y, mwdl.month(), mwdl.weekday_last())
38,40) std::chrono::year_month_weekday_last(std::chrono::year(y), mwdl.month(), mwdl.weekday_last())

### Example

Run this code

    #include <iostream>
    #include <chrono>
    using namespace std::chrono;

    int main()
    {
        std::cout << std::boolalpha;

        constexpr auto ym {2021y/8};
        std::cout << (ym == year_month(year(2021), August)) << ' ';

        constexpr auto md {9/15d};
        std::cout << (md == month_day(September, day(15))) << ' ';

        constexpr auto mdl {October/last};
        std::cout << (mdl == month_day_last(month(10))) << ' ';

        constexpr auto mw {11/Monday[3]};
        std::cout << (mw == month_weekday(November, Monday[3])) << ' ';

        constexpr auto mwdl {December/Sunday[last]};
        std::cout << (mwdl == month_weekday_last(month(12), weekday_last(Sunday))) << ' ';

        // Those three year/month/day orders that people actually use on this planet:
        constexpr auto ymd {year(2021)/January/day(23)};
        static_assert(ymd == month{1}/23/2021);
        static_assert(ymd == day{23}/1/2021);
        std::cout << (ymd == year_month_day(2021y, month(January), 23d)) << '\n';
    }

Output:

    true true true true true true

Retrieved from "https://en.cppreference.com/mwiki/index.php?title=cpp/chrono/operator_slash&oldid=146135"