std::localtime (3) - Linux Manuals
Defined in header <ctime>
std::tm* localtime( const std::time_t *time );
Converts given time since epoch as std::time_t value into calendar time, expressed in local time.
time - pointer to a time_t object to convert
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.
POSIX_specifies that the timezone information is determined by this function as if by calling tzset, which reads the environment variable TZ.
// Run this code