Dagaz means day, and encompasses the complete twenty-four hour cycle of day and night. To the ancient peoples, the day began in the evening, and included the liminal times of dawn, noon, and evening twilight. So it is that Dagaz measures one complete rotation of the Sun. The ancient peoples thought that the Sun moved from east to west during the daylight time, and from west to east under the earth at night. This may seem naïve to modern people, but when we realize that the ancients built many standing stone structures that measured the marvelous exactness of the winter and summer solstices, we must credit their ability to calculate the seasons of the year from their close observations of nature.
Dagaz is a Rune of conscious being and conscious becoming. The process of awakening consciousness, or becoming enlightened, is really the struggle between the sleep of conditioned thought and the fresh creative forces pushing us from the subconscious to wake up into Wholeness. Sowelo, the Rune that stands for the Sun, is the Rune of Wholeness, or becoming that which you already are. The Sun and the Moon are the two stellar bodies that relate most closely to Dagaz because of its inclusion of both daytime and nighttime. Because of this feature, Dagaz is also a Rune of opposites and that which lies inbetween the polarity – as the twilight lies between the two sides of the day.
Dagaz represents the ancient law of three, the duality of the polarity, and that which they become upon blending. We see this triune law reflected in the trinity of ancient goddesses; the trinity of Odin, Villi and Ve; and even the Christian trinity of Father, Son, and Holy Ghost. Writer Raphael Pattai, in the Hebrew Goddess, expressed the opinion that originally the Holy Ghost was the female aspect of Father, Mother, and Child. The best example for this expression I have found is the Valknut consisting of three intersecting triads, one of which represents the affirming force or creative force, and is made up of Odin, Villi, and Ve; one of which represents the destructive or resisting force made up of Hela, Fenris, and Jormundgand; and the triad of Being made up of the Norns Urdr, Vernđandi, and Skuld.
The point is that Dagaz, being a Rune of opposites and what lies between them, is a Rune of transformation. The transformation can be conscious, it can be one thing becoming its opposite thing, or the transformation can be a complete breakthrough to a new understanding. The knowledge you had before has been transformed by the fire of the being of life experience, and has now become understanding.
Dagaz includes consciousness, unconsciousness, and the subconscious that lies between them. It helps to understand that we are born with essence – that is our hereditary proclivities, tendencies, and so on depending on what has come down from our ancestors. We acquire education and intellectual factors that may or may not agree with our essence; the development of essence usually stops around the age of seven when children are subjected to formal education. The struggle for awakening then, must take place with the growth of essence through resistance to conditioned thought. The result, after years of struggle and self-study, may be an awakened human being. This has been simply said.
When Dagaz shows up in a reading, look for oppositional factors, the potential for transformation, or a breakthrough to a new understanding.
 Gurdjieff calls this law the Triamazikamno, and defines it as the lower blending with the higher, or the higher blending with the lower, to actualize the middle.