< cpp‎ | chrono‎ | c
Utilities library
Language support
Type support (basic types, RTTI)
Library feature-test macros (C++20)
Dynamic memory management
Program utilities
Coroutine support (C++20)
Variadic functions
Debugging support
Three-way comparison
General utilities
Date and time
Function objects
Formatting library (C++20)
Relational operators (deprecated in C++20)
Integer comparison functions
Swap and type operations
Common vocabulary types
Elementary string conversions

C-style date and time utilities
Time manipulation
Format conversions
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.


[edit] Parameters

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

[edit] 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.

[edit] 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).

[edit] 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;

Possible output:

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

[edit] See also

converts a std::tm object to a textual representation
(function) [edit]
converts a std::tm object to custom textual representation
(function) [edit]
formats and outputs a date/time value according to the specified format
(function template) [edit]
C documentation for ctime