std::chrono::system_clock
<chrono>
Class std::chrono::system_clock
represents the system-wide real time wall clock.
It may not be monotonic: on most systems, the system time can be adjusted at any moment. It is the only C++ clock that has the ability to map its time points to C-style time.
std::chrono::system_clock
meets the requirements of TrivialClock.
The epoch of system_clock
is unspecified, but most implementations use Unix Time (i.e., time since 00:00:00 Coordinated Universal Time (UTC), Thursday, 1 January 1970, not counting leap seconds).
system_clock
measures Unix Time (i.e., time since 00:00:00 Coordinated Universal Time (UTC), Thursday, 1 January 1970, not counting leap seconds).
Contents
Time point family
std::chrono
using sys_time = std::chrono::time_point <std::chrono::system_clock, Duration>;
[edit] Member types
rep
signed arithmetic type representing the number of ticks in the clock's duration
period
a std::ratio type representing the tick period of the clock, in seconds
duration
std::chrono::duration <rep, period>, capable of representing negative durations
time_point
std::chrono::time_point <std::chrono::system_clock>
[edit] Member constants
(public static member constant)
[edit] Member functions
(public static member function) [edit]
[edit] Notes
The system_clock
's time value can be internally adjusted at any time by the operating system, for example due to NTP synchronization or the user changing the system's clock. Daylight Saving Time and time zone changes, however, do not affect it since it is based on the UTC time-zone.