NAME¶

std::ctime - std::ctime

Synopsis¶

Defined in header <ctime>
char* ctime( const std::time_t* time );

Converts given time since epoch to a calendar local time and then to a textual
representation, as if by calling std::asctime(std::localtime(time)). The resulting
string has the following format:

Www Mmm dd hh:mm:ss yyyy\n

* Www - the day of the week (one of Mon, Tue, Wed, Thu, Fri, Sat, Sun).
* Mmm - the month (one of Jan, Feb, Mar, Apr, May, Jun, Jul, Aug, Sep, Oct, Nov,
Dec).
* dd - the day of the month
* hh - hours
* mm - minutes
* ss - seconds
* yyyy - years

The function does not support localization.

Parameters¶

time - pointer to a std::time_t object specifying the time to print

Return value¶

Pointer to a static null-terminated character string holding the textual
representation of date and time. The string may be shared between std::asctime and
std::ctime, and may be overwritten on each invocation of any of those functions.

Notes¶

This function returns a pointer to static data and is not thread-safe. In addition,
it modifies the static std::tm object which may be shared with std::gmtime and
std::localtime. POSIX marks this function obsolete and recommends std::strftime
instead.

The behavior may be undefined for the values of std::time_t that result in the
string longer than 25 characters (e.g. year 10000)

Example¶

// Run this code

#include <ctime>
#include <cstring>
#include <cassert>
#include <iostream>

int main()
{
std::time_t result = std::time(nullptr);
std::cout << std::ctime(&result);

char buffer[32];
std::strncpy(buffer, std::ctime(&result), 26);
assert('\n' == buffer[std::strlen(buffer)-1]);
std::cout << buffer;
}

Possible output:¶

Mon Oct 11 17:10:55 2021
Mon Oct 11 17:10:55 2021

See also¶

asctime converts a std::tm object to a textual representation
(function)
strftime converts a std::tm object to custom textual representation
(function)
put_time formats and outputs a date/time value according to the specified format
(C++11) (function template)