>  How do you calculate the day of the year in C?

    Not necessary. In the standard library header file  you
should find the struct tm listed. This has a member, tm_yday that
represents the number of days since Jan 1.

    Time functions can be a little tricky, so maybe an example would help:-

#include 
int showday(void)
{   time_t t = time(&t);
    return gmtime(&t)->tm_yday;
}
int main(void)
{   return printf("%d\n",showday()); }

    I am sorry that you find SNIPPETS hard to use. Nevertheless, the code
above is ANSI standard C snd should work on all compilers and all platforms
that comply with the standard.

    There is also strftime() available, but IIRC that requires the header
file .

Best wishes,
Bill.

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