We read a planet as being on the cusp of the next house when it is within 5 degrees of the cusp of the following house (ie in a chart with virtually equal houses). However, the turn of the planetary hours is quite specific (ie. the Sun moving through the sky), unless you allow for the Sun sitting on the cusp between two hours.

If you do think in terms of planetary hours, the hour prior to dawn on Sunday would be ruled by Mars, leading to the hour of the Sun, and then the hour before sunset would be ruled by Saturn, leading to the hour of Jupiter. In view of the Ptolemic model of the universe, the hours that follow each other would by necessity need to reflect a rotational meaning. I don't necessarily think this makes an argument for anything, but it would be easy to see how the twilight of Mars blended into the dawn of the Sun on a Sunday; or moving from the hour of Saturn to that of Jupiter would be like moving inward from the cold and dry of Saturn to blend with the moisture and warmth of Jupiter.

Aw, I don't know. This was just another way of thinking about the cuspal problem!

Up beyond the Artic Circle we have extented periods of twilight due to the elognation of the equator with the rational horizon. That sure does create some interesting play of light, but assuming that the Sun did not rize above the horizon - would there still be accounted a diurnal period?

Fascinating point. I guess this is one problem the hellenistic astrologers didn't scratch their heads trying to solve in Alexandria or Athens.

In Artic Latitudes:
In terms of calculating the planetary hours, the interval for which the culminating degree lies below the horizon, which is equal to the period where the ascendant retrogrades backwards through the signs of short ascension, this interval can be divided into 12 equal portions that may be alloted to the planetsto maintain an unbroken chain and order of rulerships.

This topic has been revived again on a new thread at :

http://skyscript.co.uk/forums/viewtopic.php?t=4404

When I have more time I will make a new comment there, but with regards to what is written above, I just want to express my opinion that although Mark referred to the first definition assigned to Hand (above) as ?the traditional outlook?, I don?t believe it is the traditional outlook. I don?t doubt Astraea, but it is a little unreliable to quote what we have heard. There is the danger that something could be misunderstood, or only slightly misquoted out of context (creating a whole new meaning), or that a speaker voices a casual opinion without giving the matter as much reflection as would happen in something meant for publication.

However, it wouldn?t surprise me if Robert Hand did say something like this and then later contradict himself. He may have wrestled with the fact that applying the whole sign approach to ancient chart descriptions can result in the Sun being placed in the 7th house yet defined as nocturnal, or vice versa (eg., Valens II.41 ? L115, XI). Or then again he may not have done any such thing, but this is one of the reasons why I am not convinced that whole sign was ever more than a convenient approach; especially given Valen?s comments about the need to calculate the ascendant and midheaven exactly, and his demonstration that the places upon a pivot point are not always 30 degrees but sometimes more or less, which therefore requires a Porphyry-style calculation (Valens III.2).

I can understand the argument that Steven is making here. This is similar to the point that Martin has made in the new thread and that is the point that I hope to find time to comment on there. What I want to say here is that I cannot help wondering whether this (IMO, misconceived) insistence that ancient authors only ever used whole sign is the reason why ?modern traditionalists? have started talking about adding in the orbs of civil or nautical twilight. Contrary to popular opinion sect wasn?t discovered by Project Hindsight; it had always been understood and applied by astrologers who practiced traditional techniques, and I don?t remember anyone ever having the opinion then, that sect could change at any moment other than when the planetary hours change.

I've collected a couple of thoughts about this issue and I'd gladly welcome your opinion.
Indeed, there's no definite border between night and daytime and the matters of twilight are also complicated by the Sun being a disc, instead of a point, the difference between topocentric and geocentric perspective, the difference of apparent and true horizon, and the refraction itself which depends on geographical height, pressure and temperature.
Therefore, I tried to approach the matter philosophically, and while I don't think there can be no other route, I think this goes along with astrological logic.
First, in our astrology it's the hour-marker that is of prime importance. It divides the sphere in two halves, so it is a border between two grades or portions (which, of course, are a matter of theoretical distribution): the portion that is not-yet-risen and the other one that is already-risen. It seems, therefore, that the critical point is the step from the night to the daytime, or, in other words, from the realm of invisibility to the realm of visibility.
Commonly, daytime is defined by Sun being above the horizon and so being visible, while night is conceived as the Sun is under the horizon and he cannot be seen. Twilight and dusk is a matter of glow coming from the Sun which precedes his rise or goes after his set. Although its a source of light, we cannot say Sun, who is the Lord of the Zodiac as it is defined and segmented by his course, is in the realm of visibility in the same way as I can't say a magnate has arrived when I've just glimpsed his convoy coming or I see them just disappearing.
(An alternative model: in polar regions, when the Sun rises towards the horizon but his disc doesn't rise actually, I think we cannot say it's daytime, even there's light. It can be true in astronomical, nautical or civil sense, but not astrologically.)
Thus, we ought to take daylight as the time when the Sun is above the horizon. But now comes another problem: as his body is not a point, which is the moment we should say he's already risen?
Comparing the childbirth, I would say the moment when his full disc is visible. A child can be said to be born really when it has fully left the body of the mother. On the other hand, a person has to be claimed to be alive if there's even the tiniest sign of life. To further adapt this logic, I would say the a person arrives my home in the very moment when he successfully crosses the threshold, and he leaves when I can close the door behind him.
To sum up, I think astrologically we can say it's daytime when the full disc of the Sun is visible, and it's night when the full disc disappeared. Certainly, this model may be argued or questioned, and also, it doesn't answer whether we should totally rely on apparent rise (that is, we should work with topocentric perspective, apparent horizon and reckon in refraction).

Hi Osthanes

That?s a very good post and I personally agree with almost everything you say, except I have an argument that proposes something different to your last point. I am currently finishing off some other work and then I was planning to make my comment in the other thread. But now I hardly know where to post ? we?ve managed to get three simultaneous threads up and running at the same time

I think it is probably best for us all to try to keep the main stem in the thread headed ?The Twilight Factor in Ancient Astrology?. I will link to your post from there, but maybe you want to reproduce your comment there too, anyway.

To prevent further confusion I am going to lock this thread and ask everyone to use the other one. If anyone wants to comment on something unique to this thread then please PM me, as I am happy to unlock it upon request.

Deb