text: #include <assert.h>
  #include <stdio.h>
  #include "monthday.h"
  
  int main(int argc, char *argv[]) {
    int m;
    int d;
  
    monthday(0, 0, &m, &d);
    assert(m == 0 && d == 0);
  
    monthday(0, 367, &m, &d);
    assert(m == 0 && d == 0);
  
    monthday(0, 60, &m, &d);
    assert(m == 2 && d == 29);
  
    assert(dayofyear(0, -1, 0) == 0);
  
    assert(dayofyear(0, 13, 1) == 0);
  
    assert(dayofyear(0, 12, 32) == 0);
  
    assert(dayofyear(2013, 2, 13) == 44);
  }
  