How Can I Precisely Get the Current Date and Time in C ?

How to Obtain Current Time and Date with Precision in C

In the realm of C programming, accessing the current date and time accurately is a common necessity. Before C 11, there were limited and somewhat antiquated methods to retrieve this information. However, with the advent of C 11 came a modern and versatile solution.

Solution: std::chrono::system_clock::now()

Since C 11, the standard library introduced the std::chrono::system_clock class, which provides a reliable and cross-platform way to access the current system time. The std::chrono::system_clock::now() method returns a system_clock::time_point object that represents the current time.

Example Code:

To illustrate its usage, consider the following example code:

#include <iostream>
#include <chrono>
#include <ctime>

int main() {
    // Get the current time
    auto start = std::chrono::system_clock::now();

    // Perform some computation here

    // Get the end time
    auto end = std::chrono::system_clock::now();

    // Calculate the elapsed time in seconds
    std::chrono::duration<double> elapsed_seconds = end - start;

    // Convert the end time to a std::time_t
    std::time_t end_time = std::chrono::system_clock::to_time_t(end);

    // Print the result
    std::cout << "Finished computation at: " << std::ctime(&end_time) << std::endl;
    std::cout << "Elapsed time: " << elapsed_seconds.count() << " seconds" << std::endl;

    return 0;
}

Output:

When executed, this code will output something similar to:

Finished computation at: Mon Oct 2 00:59:08 2017
Elapsed time: 1.23456 seconds

The system_clock::now() method provides high-precision access to the current time and is suitable for various applications, such as performance profiling and time-sensitive calculations.

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