Merging changes synced from https://github.com/MicrosoftDocs/cpp-docs-pr (branch live)

Author: opbld16

docs/standard-library/chrono-functions.md

@@ -1,7 +1,7 @@
 ---
 description: "Learn more about: <chrono> functions"
 title: "<chrono> functions"
-ms.date: 6/16/2021
+ms.date: "08/13/2021"
 f1_keywords: ["chrono/std::duration_cast", "chrono/std::time_point_cast", "chrono/std::chrono::duration_cast", "chrono/std::chrono::time_point_cast", "chrono/std::chrono::from_stream", "chrono/std::chrono::floor", "chrono/std::chrono::ceil", "chrono/std::chrono::round", "chrono/std::chrono::is_am", "chrono/std::chrono::is_pm", "chrono/std::chrono::make12", "chrono/std::chrono::make24", "chrono/std::chrono::get_leap_second_info", "chrono/std::chrono::get_tzdb", "chrono/std::chrono::get_tzdb_list", "chrono/std::chrono::locate_zone", "chrono/std::chrono::current_zone", "chrono/std::chrono::reload_tzdb", "chrono/std::chrono::remote_version"]
 helpviewer_keywords: ["std::duration_cast function", "std::time_point_cast function", "std::chrono::duration_cast function", "std::chrono::time_point_cast function", "std::chrono::from_stream function", "std::chrono::floor function", "std::chrono::ceil function", "std::chrono::round function", "std::chrono::is_am function", "std::chrono::is_pm function", "std::chrono::make12 function", "std::chrono::make24 function", "std::chrono::get_leap_second_info function", "std::chrono::get_tzdb function", "std::chrono::get_tzdb_list function", "std::chrono::locate_zone function", "std::chrono::current_zone function", "std::chrono::reload_tzdb function", "std::chrono::remote_version function"]
 ---
@@ -352,13 +352,13 @@ The format string used to match the input. See [Parse format strings](#parse-for
 The `file_time` parsed from the stream.
 
 *`gt`*\
-The `gps_time` parsed from the stream.
+The [`gps_time`](chrono.md#typedefs)  parsed from the stream.
 
 *`is`*\
 The input stream to parse.
 
 *`lt`*\
-The `local_time` parsed from the stream.
+The [`local_time`](chrono.md#typedefs) parsed from the stream.
 
 *`m`*\
 The `month` parsed from the stream.
@@ -370,13 +370,13 @@ The `month_day` parsed from the stream.
 If *`offset`* isn't `nullptr`, and the format specifier `%z` or modified variant such as `%Ez` or `%0z` is specified, and the parse is successful, then *`offset`* points to the parsed value.
 
 *`st`*\
-The `system_time` parsed from the stream.
+The [`sys_time`](chrono.md#typedefs) parsed from the stream.
 
 *`tt`*\
-The `tai_time` parsed from the stream.
+The [`tai_time`](chrono.md#typedefs) parsed from the stream.
 
 *`ut`*\
-The `utc_time` parsed from the stream.
+The [`utc_time`](chrono.md#typedefs) parsed from the stream.
 
 *`wd`*\
 The `weekday` parsed from the stream.
@@ -538,12 +538,11 @@ In ISO 8601, weeks begin with Monday. The first week of the year must include Ja
 | `year_month_weekday_last` | D, F, g, G, j, U, V, W, Y, y, C, b, h, B, m, d, e, a, A, u, w |
 | `zoned_time` | z, Z, c, x, X, D, F, Y, C, y, b, B, h, m, d, e, a, A, u, w, H, I, M, S, r, R, T, p, g, G, U, V, W |
 
-<a name="notice"></a><sup>1</sup>The implementation is currently consistent with [strftime](../c-runtime-library/reference/strftime-wcsftime-strftime-l-wcsftime-l.md) in that although `O` (letter O) and `e` are accepted, they are ignored. That is, `"%Od"` is interpreted as `"%d"`.
+<a name="notice"></a><sup>1</sup>The implementation is currently consistent with [strftime](../c-runtime-library/reference/strftime-wcsftime-strftime-l-wcsftime-l.md) in that although `O` (letter O) and `e` are accepted, they're ignored. That is, `"%Od"` is interpreted as `"%d"`.
 
 ## <a name="std-chrono-get-leap-second-info"></a> `get_leap_second_info`
 
-Returns a [`leap_second_info`](./leap-second-info-struct.md)\
- for the specified time.
+Returns a [`leap_second_info`](./leap-second-info-struct.md) for the specified time. This provides info about whether the supplied time occurs during a leap second insertion. It also provides the number of leap seconds that have been added between January 1, 1970 and the specified time. A leap second insertion occurs when the International Earth Rotation and Reference Systems Service (IERS) declares that a leap second will be added (resulting in a 61 second minute) to account for the difference between atomic time and time tracked by measuring the rotation of the earth, which is irregular, and is gradually slowing.
 
 ### Syntax
 

docs/standard-library/chrono-operators.md

@@ -1,8 +1,8 @@
 ---
 description: "Learn more about: <chrono> operators"
 title: "<chrono> operators"
-ms.date: "6/30/2021"
-f1_keywords: ["chrono/std::operator modulo", "chrono/std::operator+", "chrono/std::chrono::day::operator+", "chrono/std::chrono::duration::operator+", "chrono/std::chrono::month::operator+", "chrono/std::chrono::time_point::operator+", "chrono/std::chrono::weekday::operator+", "chrono/std::chrono::year_month::operator+", "chrono/std::chrono::year::operator+", "chrono/std::chrono::year_month_day::operator+", "chrono/std::chrono::year_month_day_last::operator+", "chrono/std::chrono::year_month_weekday::operator+", "chrono/std::chrono::year_month_weekday_last::operator+", "chrono/std::operator!=", "chrono/std::operator*", "chrono/std::operator/", "chrono/std::operator-", "chrono/std::operator<", "chrono/std::operator<=", "chrono/std::operator<", "chrono/std::operator==", "chrono/std::operator>>", "chrono/std::operator<=>", "chrono/std::chrono::day::operator<=>", "chrono/std::chrono::month::operator<=>", "chrono/std::chrono::year::operator<=>", "chrono/std::chrono::year_month::operator<=>", "chrono/std::chrono::time_point::operator<=>", "chrono/std::chrono::duration::operator<=>", "chrono/std::chrono::month_day_last::operator<=>", "chrono/std::chrono::year_month_day_last::operator<=>", "chrono/std::operator==", "chrono/std::chrono::year::operator<==>", "chrono/std::chrono::day::operator==", "chrono/std::chrono::duration::operator==", "chrono/std::chrono::month::operator==", "chrono/std::chrono::month_day::operator==", "chrono/std::chrono::month_day_last::operator==", "chrono/std::chrono::month_weekday::operator==", "chrono/std::chrono::month_weekday_last::operator==", "chrono/std::chrono::time_point::operator==", "chrono/std::chrono::weekday::operator==", "chrono/std::chrono::year_month::operator==", "chrono/std::chrono::year::operator==", "chrono/std::chrono::year_month_day::operator==", "chrono/std::chrono::year_month_day_last::operator==", "chrono/std::chrono::year_month_weekday_last::operator==", "chrono/std::chrono::year_month_weekday::operator==", "chrono/std::chrono::month_weekday_last::operator==", "chrono/std::chrono::weekday::operator==", "chrono/std::chrono::weekday_last::operator==", "chrono/std::chrono::year_month_weekday_indexed::operator==", "chrono/std::chrono::year_month_weekday_last::operator==", "chrono/std::chrono::year::operator==", "chrono/std::chrono::year_month::operator==",  "chrono/std::chrono::year_month_day::operator==", "chrono/std::chrono::year_month_day_last::operator==", "chrono/std::operator-", "chrono/std::chrono::day::operator-", "chrono/std::chrono::duration::operator-", "chrono/std::chrono::month::operator-", "chrono/std::chrono::time_point::operator-", "chrono/std::chrono::weekday::operator-", "chrono/std::chrono::year_month::operator-", "chrono/std::chrono::year::operator-", "chrono/std::chrono::year_month_day::operator-", "chrono/std::chrono::year_month_day_last::operator-", "chrono/std::chrono::year_month_weekday::operator-", "chrono/std::chrono::year_month_weekday_last::operator-", "chrono/std::chrono::day::operator<<", "chrono/std::chrono::hh_mm_ss::operator<<", "chrono/std::chrono::month_day::operator<<", "chrono/std::chrono::month_day_last::operator<<", "chrono/std::chrono::month_weekday::operator<<", "chrono/std::chrono::month_weekday_last::operator<<", "chrono/std::chrono::weekday::operator<<", "chrono/std::chrono::weekday_indexed::operator<<", "chrono/std::chrono::weekday_last::operator<<", "chrono/std::chrono::year::operator<<", "chrono/std::chrono::year_month_day::operator<<", "chrono/std::chrono::year_month_day_last::operator<<", "chrono/std::chrono::year_month_weekday::operator<<"]
+ms.date: "08/13/2021"
+f1_keywords: ["chrono/std::operator modulo", "chrono/std::operator+", "chrono/std::chrono::day::operator+", "chrono/std::chrono::duration::operator+", "chrono/std::chrono::month::operator+", "chrono/std::chrono::time_point::operator+", "chrono/std::chrono::weekday::operator+", "chrono/std::chrono::year_month::operator+", "chrono/std::chrono::year::operator+", "chrono/std::chrono::year_month_day::operator+", "chrono/std::chrono::year_month_day_last::operator+", "chrono/std::chrono::year_month_weekday::operator+", "chrono/std::chrono::year_month_weekday_last::operator+", "chrono/std::operator!=", "chrono/std::operator*", "chrono/std::operator/", "chrono/std::operator-", "chrono/std::operator<", "chrono/std::operator<=", "chrono/std::operator<", "chrono/std::operator==", "chrono/std::operator>>", "chrono/std::operator<=>", "chrono/std::chrono::day::operator<=>", "chrono/std::chrono::month::operator<=>", "chrono/std::chrono::year::operator<=>", "chrono/std::chrono::year_month::operator<=>", "chrono/std::chrono::time_point::operator<=>", "chrono/std::chrono::duration::operator<=>", "chrono/std::chrono::month_day_last::operator<=>", "chrono/std::chrono::year_month_day_last::operator<=>", "chrono/std::operator==", "chrono/std::chrono::year::operator<==>", "chrono/std::chrono::day::operator==", "chrono/std::chrono::duration::operator==", "chrono/std::chrono::month::operator==", "chrono/std::chrono::month_day::operator==", "chrono/std::chrono::month_day_last::operator==", "chrono/std::chrono::month_weekday::operator==", "chrono/std::chrono::month_weekday_last::operator==", "chrono/std::chrono::time_point::operator==", "chrono/std::chrono::weekday::operator==", "chrono/std::chrono::year_month::operator==", "chrono/std::chrono::year::operator==", "chrono/std::chrono::year_month_day::operator==", "chrono/std::chrono::year_month_day_last::operator==", "chrono/std::chrono::year_month_weekday_last::operator==", "chrono/std::chrono::year_month_weekday::operator==", "chrono/std::chrono::month_weekday_last::operator==", "chrono/std::chrono::weekday::operator==", "chrono/std::chrono::weekday_last::operator==", "chrono/std::chrono::year_month_weekday_indexed::operator==", "chrono/std::chrono::year_month_weekday_last::operator==", "chrono/std::chrono::year::operator==", "chrono/std::chrono::year_month::operator==",  "chrono/std::chrono::year_month_day::operator==", "chrono/std::chrono::year_month_day_last::operator==", "chrono/std::operator-", "chrono/std::chrono::day::operator-", "chrono/std::chrono::duration::operator-", "chrono/std::chrono::month::operator-", "chrono/std::chrono::time_point::operator-", "chrono/std::chrono::weekday::operator-", "chrono/std::chrono::year_month::operator-", "chrono/std::chrono::year::operator-", "chrono/std::chrono::year_month_day::operator-", "chrono/std::chrono::year_month_day_last::operator-", "chrono/std::chrono::year_month_weekday::operator-", "chrono/std::chrono::year_month_weekday_last::operator-", "chrono/std::chrono::day::operator<<", "chrono/std::chrono::hh_mm_ss::operator<<", "chrono/std::chrono::month_day::operator<<", "chrono/std::chrono::month_day_last::operator<<", "chrono/std::chrono::month_weekday::operator<<", "chrono/std::chrono::month_weekday_last::operator<<", "chrono/std::chrono::weekday::operator<<", "chrono/std::chrono::weekday_indexed::operator<<", "chrono/std::chrono::weekday_last::operator<<", "chrono/std::chrono::year::operator<<", "chrono/std::chrono::year_month_day::operator<<", "chrono/std::chrono::year_month_day_last::operator<<", "chrono/std::chrono::year_month_weekday::operator<<", "chrono/std::chrono::utc_time::operator<<", "chrono/std::chrono::tai_time::operator<<", "chrono/std::chrono::gps_time::operator<<", "chrono/std::chrono::local_time::operator<<", "chrono/std::chrono::file_time::operator<<"]
 ---
 # `<chrono>` operators
 
@@ -131,7 +131,7 @@ constexpr year_month_weekday_last operator+(const years& dy, const year_month_we
 
 16\) Returns `(ymwdl.year() / ymwdl.month() + dm) / ymwdl.weekday_last()`. Note: The `/` used here is not a division operator but the date operator.
 
-17\) Returns Returns: `ymwdl + dy`
+17\) Returns: `ymwdl + dy`
 
 ### Example: `operator+`
 
@@ -804,12 +804,17 @@ true true false
 Output the following types to a stream:
 
 - [`day`](day-class.md)
+- [`file_time`](chrono.md)
+- [`gps_time`](gps-clock-class.md)
 - [`hh_mm_ss`](hhmmss-class.md)
+- [`local_time`](local_t.md)
 - [`month`](month-class.md)
 - [`month_day`](month-day-class.md)
 - [`month_day_last`](month-day-last-class.md)
 - [`month_weekday`](month-weekday-class.md)
 - [`month_weekday_last`](month-weekday-last-class.md)
+- [`tai_time`](tai-clock-class.md)
+- [`utc_time`](utc-clock-class.md)
 - [`weekday`](weekday-class.md)
 - [`weekday_indexed`](weekdayindexed-class.md)
 - [`weekday_last`](weekdaylast-class.md)
@@ -899,7 +904,27 @@ operator<<(basic_ostream<CharT, Traits>& os, const year_month_weekday& ymwd); //
 // 16) year_month_weekday_last
 template<class CharT, class Traits>
 basic_ostream<CharT, Traits>&
-operator<<(basic_ostream<CharT, Traits>& os, const year_month_weekday_last& ymwdl);
+operator<<(basic_ostream<CharT, Traits>& os, const year_month_weekday_last& ymwdl); // C++ 20
+
+// 17) tai_time
+template<class CharT, class Traits, class Duration>
+basic_ostream<CharT, Traits>&
+operator<<(basic_ostream<CharT, Traits>& os, const tai_time<Duration>& t); // C++ 20
+
+// 18) utc_time
+template<class CharT, class Traits, class Duration>
+basic_ostream<CharT, traits>&
+operator<<(basic_ostream<CharT, Traits>& os, const utc_time<Duration>& t); // C++ 20
+
+// 19) gps_time
+template<class CharT, class Traits, class Duration>
+basic_ostream<CharT, Traits>&
+operator<<(basic_ostream<CharT, Traits>& os, const gps_time<Duration>& t); // C++ 20
+
+// 20) local_time
+template<class CharT, class Traits, class Duration>
+basic_ostream<CharT, Traits>&
+operator<<(basic_ostream<CharT, Traits>& os, const local_time<Duration>& t); // C++ 20
 ```
 
 ### Parameters
@@ -934,6 +959,9 @@ The `month_weekday` to output.
 *`mwdl`*\
 The `month_weekday_last` to output.
 
+*`t`*\
+The `local_time`, `gps_time`, `tai_time`, or `utc_time` to output.
+
 *`wd`*\
 The `weekday` to output.
 
@@ -969,7 +997,7 @@ The output stream you passed in, `os`
 
 1\) The `day` value is output as a decimal number, with a leading zero if the result would be a single digit. If `!d.ok()`, then " isn't a valid day" is appended to the output.
 
-2\) The `hh_mm_ss` value is output as hours:minutes:seconds:thousands of seconds. For example, `"00:00:05.721`"
+2\) The `hh_mm_ss` value is output as hours:minutes:seconds:thousandths of seconds. For example, `"00:00:05.721`"
 
 3\) The abbreviated month name, using the locale associated with `os`, is output. For example, `Jan`. If `!m.ok()`, then `" is not a valid month"` is appended to the output.
 
@@ -999,6 +1027,38 @@ The output stream you passed in, `os`
 
 16\) The `year_month_weekday_last` is output in the form yyyy/month/weekday[last]. For example, `1996/Jan/Wed[last]`
 
+17\) The `tai_time` is output in the form yyyy-mm-dd hh:mm:ss.sssssss. For example, `2021-08-13 23:23:08.4358666`
+
+18\) The `utc_time` is output in the form yyyy-mm-dd hh:mm:ss.sssssss. For example, `2021-08-13 23:23:08.4358666`
+
+19\) The `gps_time` is output in the form yyyy-mm-dd hh:mm:ss.sssssss. For example, `2021-08-13 23:23:08.4358666`
+
+20\) The `local_time` is output as the number of seconds since the clock's epoch. It's output as though by `os << std::chrono::sys_time<Duration>(some_local_time.time_since_epoch());`. For example, if `some_local_time` is August 18, 2021 3:13pm, the output is `1597792380`.
+
+### Example: `operator<<`
+
+```cpp
+// compile using: /std:c++latest
+#include <iostream>
+#include <chrono>
+
+using namespace std::chrono;
+
+int main()
+{
+    std::cout << utc_clock::now() << '\n';
+
+    year_month ym{ 2021y / April };
+    std::cout << ym;
+    return 0;
+}
+```
+
+```output
+2021-08-16 20:47:05.6299822
+2021/Apr
+```
+
 ## <a name="op_modulo"></a> `operator modulo`
 
 Operator for modulo operations on [`duration`](../standard-library/duration-class.md) objects.