std::gmtime

From cppreference.com
< cpplrm; | chronolrm; | c
Date and time utilities
(C++11)
(C++11)
Clocks
(C++20)
(C++20)
(C++20)
(C++20)
(C++20)
Calendars
(C++20)
(C++20)
(C++20)
(C++20)
(C++20)
Time zones
(C++20)
(C++20)
(C++20)
(C++20)
(C++20)
(C++20)
C-style date and time
C-style date and time utilities
Functions
Time manipulation
Format conversions
gmtime
Constants
Types
(C++17)
Defined in header <ctime>
std::tm* gmtime( const std::time_t* time );

Converts given time since epoch as std::time_t value into calendar time, expressed in Coordinated Universal Time (UTC).

Parameters

time - pointer to a time_t object to convert

Return value

Pointer to a static internal std::tm object on success, or null pointer otherwise. The structure may be shared between std::gmtime, std::localtime, and std::ctime and may be overwritten on each invocation.

Notes

This function may not be thread-safe.

POSIX requires that this function sets errno to EOVERFLOW if it fails because the argument is too large.

Example

#include <iostream>
#include <iomanip>
#include <ctime>

int main()
{
    std::time_t t = std::time(nullptr);
    std::cout << "UTC:   " << std::put_time(std::gmtime(&t), "%c%Z") << '\n';
    std::cout << "local: " << std::put_time(std::localtime(&t), "%c%Z") << '\n';
}

Output:

UTC:   Wed Dec 28 11:44:28 2011 GMT
local: Wed Dec 28 06:44:28 2011 EST

See also

converts time since epoch to calendar time expressed as local time
(function)