Write a program to get and set system current date and time in C language

Mastering System Date and Time Manipulation in C Language

In the realm of programming, managing data and time is a fundamental aspect across various applications. Whether you're developing a scheduling system, logging events, or simply displaying the current date and time, having control over system date and time in your C programs is crucial. In this tutorial, we'll delve into the intricacies of fetching and setting the system date and time using the C programming language.

Understanding Time in C

Before we dive into implementation, let's grasp the basic concepts. In C, time is typically represented using the `time_t` structure from the `time.h` header file. This structure stores the number of seconds elapsed since the Unix epoch (January 1, 1970, UTC). Additionally, C provides the `struct tm` structure to hold broken-down time information such as seconds, minutes, hours, days, months, and years.

Getting the Current System Date and Time

Fetching the current system date and time involves using the `time()` function, which returns the current calendar time as a `time_t` object. Here's a simple program to accomplish this:

#include <stdio.h>

#include <time.h>

int main() {

    // Obtain current time

    time_t currentTime;

    time(&currentTime);

    // Convert the current time to local time

    struct tm *localTime = localtime(&currentTime);

    // Display the current date and time

    printf("Current Date and Time: %s", asctime(localTime));

    return 0;

}

In this program:

• `time(&currentTime)` retrieves the current system time and stores it in the `currentTime` variable.
• `localtime(&currentTime)` converts the `time_t` value into a `tm` structure representing the local time.
• `asctime(localTime)` converts the `tm` structure to a human-readable string format.

Setting the System Date and Time

Setting the system date and time programmatically requires a bit more effort due to platform dependencies. However, on Unix-like systems, you can use the `date` command via system calls to change the system time. Here's how you can achieve this in C:

#include <stdio.h>

#include <stdlib.h>

int main() {

    // Set new system date and time

    system("date MMDDhhmm[[CC]YY][.ss]");

    return 0;

}

In this program, replace `MM` with the desired month, `DD` with the day, `hh` with the hour, `mm` with the minute, `CC` with the century (optional), `YY` with the year, and `ss` with the second (optional). Execute the program with appropriate values to set the system date and time accordingly.

Conclusion

Manipulating system date and time in C empowers developers to create robust applications with accurate time tracking and scheduling capabilities. By leveraging the standard C library functions and system calls, you can seamlessly retrieve and modify date and time information, catering to diverse application requirements. As you continue to explore C programming, mastering time management will undoubtedly enhance the functionality and reliability of your projects. Happy coding!