NAME¶

std::chrono::gps_clock - std::chrono::gps_clock

Synopsis¶

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

The clock std::chrono::gps_clock is a Clock that represents Global Positioning
System (GPS) time. It measures time since 00:00:00, 6 January 1980 UTC.

Leap seconds are not inserted into GPS. Thus, every time a leap second is inserted
into UTC, UTC falls another second behind GPS. As of December 2017, UTC is 18
seconds behind GPS, reflecting the 18 leap seconds inserted between 1980 and 2017.
Thus, 2018-01-01 00:00:00 UTC is equivalent to 2018-01-01 00:00:18 GPS. GPS is a
constant 19 seconds behind TAI.

gps_clock meets the Clock requirements. It does not meet the TrivialClock
requirements unless the implementation can guarantee that now() does not throw an
exception.

Time point family

Defined in namespace std::chrono
template<class Duration>
using gps_time = std::chrono::time_point<std::chrono::gps_clock, (since C++20)
Duration>;
using gps_seconds = gps_time<std::chrono::seconds>; (since C++20)

operator<<(std::chrono::gps_time) performs stream output on a gps_time
(C++20) (function template)
from_stream(std::chrono::gps_time) parses a gps_time from a stream according to
(C++20) the provided format
(function template)
std::formatter<std::chrono::gps_time> specialization of std::formatter that formats
(C++20) a gps_time according to the provided format
(class template specialization)

Member types¶

Member type Definition
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::gps_clock>

Member constants¶

true if the time between ticks is always constant, i.e.
constexpr bool is_steady calls to now() return values that increase monotonically
[static] even in case of some external clock adjustment, otherwise
false
(public static member constant)

Member functions¶

now returns a std::chrono::time_point representing the current point in time
[static] (public static member function)
to_utc converts a gps_time to utc_time
[static] (public static member function)
from_utc converts a utc_time to gps_time
[static] (public static member function)