Date and time utilities

C++ includes support for two types of time manipulation:

The chrono library, a flexible collection of types that track time with varying degrees of precision (e.g. std::chrono::time_point).
C-style date and time library (e.g. std::time)

`chrono` library

The chrono library defines three main types (durations, clocks, and time points) as well as utility functions and common typedefs.

Duration

A duration consists of a span of time, defined as some number of ticks of some time unit. For example, "42 seconds" could be represented by a duration consisting of 42 ticks of a 1-second time unit.

Defined in header `<chrono>`
Defined in namespace `std::chrono`
duration (C++11)	a time interval (class template)

Clocks

A clock consists of a starting point (or epoch) and a tick rate. For example, a clock may have an epoch of January 1, 1970 and tick every second. C++ defines three clock types:

Defined in header `<chrono>`
Defined in namespace `std::chrono`
system_clock (C++11)	wall clock time from the system-wide realtime clock (class)
steady_clock (C++11)	monotonic clock that will never be adjusted (class)
high_resolution_clock (C++11)	the clock with the shortest tick period available (class)

Time point

A time point is a duration of time that has passed since the epoch of specific clock.

Defined in header `<chrono>`
Defined in namespace `std::chrono`
time_point (C++11)	a point in time (class template)

C-style date and time library

Also provided are the C-style date and time functions, such as std::time_t, std::difftime, and CLOCKS_PER_SEC.

Language
Standard library headers
Concepts
Utilities library
Strings library
Containers library
Algorithms library
Iterators library
Numerics library
Input/output library
Localizations library
Regular expressions library (C++11)
Atomic operations library (C++11)
Thread support library (C++11)
Filesystem library (C++17)
Technical Specifications