current date - 3 days ago

Hi,

I need to find the date 3 days ago from the current date (current date - 3) in C. Could anyone tell me how I can acheive this. Any help would be greatly appreciated.

Thanks

Code:

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#include <stdio.h>
#include <time.h>

time_t tt = time(NULL);  // Seconds since  midnight (00:00:00), January 1, 1970

time_t tt_3daysago = tt - 3 * 24 * 60 * 60;  // minus 3 days in seconds

struct tm *t3daysago = localtime(&tt_3daysago);

printf("%s", asctime(t3daysago)

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Something along those lines should help.

Read the current time in seconds and reduce 30*30*24*3=259200 from it. Use #include <time.h>

Code:

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#include <stdio.h>
#include <stdlib.h>
#include <time.h>

int main ( ) {
    time_t  now;
    struct tm tm_now;

    now = time(NULL);
    printf( "Now=%s\n", asctime(localtime(&now)) );
    tm_now = *localtime(&now);
    tm_now.tm_mday -= 3;        /* 3 days ago */
    now = mktime( &tm_now );
    printf( "Earlier=%s\n", asctime(localtime(&now)) );
    return 0;
}

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You can make all sorts of changes to tm_now, and the mktime() call will fix things up for you (within reason)