hey renjer,
you are right, i use day and night formula as most sources advise it and to be honest , i read some good explanations + when i was doing it all manually i got some good results.
i remember a specific passage (dont know where though) that said that ptolemy was misunderstood with his conception of only day formula (could well be astro.com page on pof)
if someone has some evidence i can always change it , but for now ill leave it as it is
(colour method suggested palace and it was correct
thanks anyway and good luck