std:: ctime

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

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

#include <cassert>
#include <cstring>
#include <ctime>
#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;
}

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

See also