std::gmtime (3) - Linux Manuals

std::gmtime: std::gmtime


std::gmtime - std::gmtime


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).


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.


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.


// Run this code

  #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';


  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
localtime (function)