Im pretty sure that the text I used is plagiarized from Practical Astronomy with your Calculator by Peter DuffetSmith I dont have my copy of Meeus here but Ill get it  be patient Youre probably right that a Julian day is a double and that a Julian day number is an int Either way a function that returns a double is much more useful since a double is required for astronomical calculations and it can be rounded to an int Stay tuned    Senor Cuete