//en.cppreference.com/w/c/language/struct_initialization.html
#include <stdio.h>
#include <time.h>
int main(void)
{
char buff[70];
// designated initializers simplify the use of structs whose
// order of members is unspecified
struct tm my_time = { .tm_year=2012-1900, .tm_mon=9, .tm_mday=9,
.tm_hour=8, .tm_min=10, .tm_sec=20 };
strftime(buff, sizeof buff, "%A %c", &my_time);
puts(buff);
}