So What Night is Full Moon?

On our Facebook page today I made a note that the Moon will be Full tomorrow morning, but that many groups will be holding their Full Moon Ceremony (and possibly Samhain too) tonight.
     In our last Newsletter we had an article which discussed this topic, answering the question: 'Is there a difference between astrological New Moon and Magical New Moon'. So I will use an extract from that article here:

     Our ancestors were not as fixated on precise timing as we in the modern world. Originally the only clock in a village would be the one on the church tower, and when these were first installed they only had one hand, to indicate the nearest hour. Chiming clocks strike the quarter hours because that was the most precise any country person wanted to be.
     ... When you observe the Moon regularly, you will see that its shape changes a little each night, but like a very slow flicker book, the changes are so slight, it is difficult to tell the difference from one evening to the next. So when you look at the Full Moon, in practise there are three nights (usually) when the Moon appears to be Full.
     The same thing happens around New Moon, but here we have an added dimension to the tale: the astrological moment of the New Moon falls in the middle of what we know magically as the Dark of the Moon.
     The Dark of the Moon is that time when there seems to be no Moon in the sky, the Moon vanishes all together, so in magical terms the New Moon does not occur until the thinnest sliver of the Waxing Moon can be observed in the sky. This is usually a couple of nights after the Astrological New Moon.
     This also explains why sometimes there are said to be four faces of the Goddess: The New, Waxing Moon is the Maiden, the Full Moon is the Bright Mother, the Waning Moon is the Crone, and the Dark of the Moon belongs to the Dark Mother.
     What this boils down to is that we actually have a little more leeway than it would appear to hold our Full Moon ritual. We can hold it on any of the three nights around the time of the Full Moon, which means we can find a time most convenient for our purposes.