Print system time in C++

The C++ standard library does not provide a proper date type. C++ inherits the structs and functions for date and time manipulation from C. To access date and time related functions and structures, you would need to include <ctime> header file in your C++ program.

There are four time-related types: clock_t, time_t, size_t, and tm. The types - clock_t, size_t and time_t are capable of representing the system time and date as some sort of integer.

The structure type tm holds the date and time in the form of a C structure having the following elements -

struct tm {
   int tm_sec; // seconds of minutes from 0 to 61
   int tm_min; // minutes of hour from 0 to 59
   int tm_hour; // hours of day from 0 to 24
   int tm_mday; // day of month from 1 to 31
   int tm_mon; // month of year from 0 to 11
   int tm_year; // year since 1900
   int tm_wday; // days since sunday
   int tm_yday; // days since January 1st
   int tm_isdst; // hours of daylight savings time
}

Suppose you want to retrieve the current system date and time, either as a local time or as a Coordinated Universal Time (UTC). Following is the example to achieve the same –

Example

 Live Demo

#include <iostream>
#include <ctime>
using namespace std;
int main() {
   // current date/time based on current system
   time_t now = time(0);
   char* dt = ctime(&now); // convert now to string form
   cout << "The local date and time is: " << dt << endl;
   // convert now to tm struct for UTC
   tm *gmtm = gmtime(&now);
   dt = asctime(gmtm);
   cout << "The UTC date and time is:"<< dt << endl;
}

Output

The local date and time is: Fri Mar 22 13:07:39 2019
The UTC date and time is:Fri Mar 22 07:37:39 2019