Dagaz is the letter D
Anglo-Saxon Rune Poem (from ragweedforge.com)
Day, the glorious light of the Creator, is sent by the Lord;
it is beloved of men, a source of hope and happiness to rich and poor,and of service to all
Dagaz or Day is definitely one of more benevolent runes of the whole Futhorc. It is of course the shining power of daytime. Sowilo is the sun, the source of the light, Dagaz is the light itself, which chases away the dangers that lurk in darkness, is filled with warmth, and as the symbolism of dawn, brings hope, new opportunities and the awakening of possibilities.
From an esoteric perspective, Dagaz is all of those things. It is the power of daylight and day time, so it is protective in a sense, as it repels those things which flee from daylight. By bringing warmth and light to people, it can ease sadness and distress, and signify and end to those things. It is also a symbol of time, different then Jera (year) as Dagaz is a shorter unit of time. In that sense, it signifies change that comes quickly and gently, like the dawn breaking in the morning. These changes are usually benevolent, showing the end to previous state and the beginning of a new state. Often this is marked by significant changes, and so Dagaz also symbolizes the forces of change and transformation.