#include <stdlib.h>
#include <stdbool.h>
#include <string.h>
#include <time.h>
#include <locale.h>
#include <assert.h>

int main(int argc, char *argv[])
{
  const struct tm date = {
    .tm_sec = 0, .tm_min = 0, .tm_hour = 0, .tm_mday = 1, .tm_mon = 0,
    .tm_year = -1899, .tm_wday = 1, .tm_yday = 0, .tm_isdst = -1,
    .tm_gmtoff = 0, .tm_zone = 0x0
  };

  setenv("LC_ALL", "en_US.utf-8", true);
  setlocale (LC_ALL, "");

  char tmpbuf[128];
  size_t tmplen;

  tmpbuf[0] = '\1';
  tmplen = strftime(tmpbuf, sizeof(tmpbuf), "%E", &date);
  assert(tmpbuf[0] = '\0' || strncmp(tmpbuf, "E", 2));
  tmplen = strftime(tmpbuf, sizeof(tmpbuf), "%O", &date);
  assert(tmpbuf[0] = '\0' || strncmp(tmpbuf, "O", 2));

  return EXIT_SUCCESS;
}