text: #ifndef ACT360_H
  #define ACT360_H
  
  #include "julianday/julianday.h"
  #include <stdlib.h> //exit
  #include <stdio.h>
  
  double act360(int y1, int m1, int d1, 
                int y2, int m2, int d2);
  
  #endif /* ACT360_H */
  