Thanks for your reply, but the problem still exists.
I updated the code (below) , but still getting strange unexpected results.
#include <spa.h>
spa_data spa;
int result;
float min, sec;
void setup()
{
Serial.begin(9600);
}
void loop()
{
spa.year = 2003;
spa.month = 10;
spa.day = 17;
spa.hour = 12;
spa.minute = 30;
spa.second = 30;
spa.timezone = 7.0;
spa.delta_t = 67;
spa.longitude = -105.1786;
spa.latitude = 39.742476;
spa.elevation = 1830.14;
spa.pressure = 820;
spa.temperature = 11;
spa.slope = 30;
spa.azm_rotation = -10;
spa.atmos_refract = 0.5667;
spa.function = SPA_ALL;
result = spa_calculate(&spa);
if (result == 0)
{
Serial.print ("Julian Day: ");
Serial.println(spa.jd);
}
else
Serial.print ("SPA Error Code: ");
Serial.println(result);
delay(10000);
}