Manipulating Dates and Times

In C++, manipulating dates and times is made easier with the help of C++ libraries. These libraries provide functionality to perform various operations on date and time objects.

Let's start by learning how to obtain the current date and time based on the system's clock. We can use the std::time() function to get the current time as a time_t object representing the number of seconds since the UNIX epoch (January 1, 1970):

1std::time_t now = std::time(0);

To convert the time_t value to a string representing the local date and time, we can use the std::ctime() function:

1char* dt = std::ctime(&now);

Similarly, we can obtain the UTC (Coordinated Universal Time) date and time by converting the time_t value to the std::tm structure using the std::gmtime() function:

1std::tm* gmtm = std::gmtime(&now);

We can then convert the std::tm structure back to a string representation using the std::asctime() function:

1dt = std::asctime(gmtm);

Finally, we can output the local date and time as well as the UTC date and time using std::cout:

1std::cout << "Local date and time: " << dt;
2std::cout << "UTC date and time: " << dt;

Try running the code above to see the output. You will observe the difference between the local date and time and the UTC date and time.

xxxxxxxxxx

#include <iostream>

#include <ctime>

​

int main() {

  // Get the current date and time

  std::time_t now = std::time(0);

​

  // Convert the time_t object to a string representing the local date and time

  char* dt = std::ctime(&now);

  std::cout << "Local date and time: " << dt;

​

  // Convert the time_t object to the tm structure representing UTC date and time

  std::tm* gmtm = std::gmtime(&now);

​

  // Convert the tm structure back to a string representation

  dt = std::asctime(gmtm);

  std::cout << "UTC date and time: " << dt;

​

  return 0;

}