prog.9.5.c

// Program to update the time by one second

#include <stdio.h>

struct time
{
	int hour;
	int minutes;
	int seconds;
};

int main (void)
{
	struct time timeUpdate (struct time now);
	struct time currentTime, nextTime;

	printf ("Enter the time (hh:mm:ss): ");
	scanf  ("%i:%i:%i", &currentTime.hour,
			&currentTime.minutes, &currentTime.seconds);

	nextTime = timeUpdate (currentTime);

	printf ("Updated time is %.2i:%.2i:%.2i\n", nextTime.hour,
			nextTime.minutes, nextTime.seconds);

	return 0;
}

// Function to update the time by one second

struct time timeUpdate (struct time now)
{
	++now.seconds;

	if ( now.seconds == 60 ) {		// next minute
		now.seconds = 0;
		++now.minutes;

		if ( now.minutes == 60 ) {	// next hour
			now.minutes = 0;
			++now.hour;

			if ( now.hour == 24 )	// midnight
				now.hour = 0;
		}
	}

	return now;
}