Answer:
I never was but am always to be, and everyone looks forward to me
What can touch someone once and last them a lifetime?
Longer than a decade and shorter than a milennium
I am a king but also a common device of measure. What am I?
Tear one off and scratch my head, what once was red is black instead!
Written on with words of white, Has the color of the night, Is the teacher's best delight, And a student's daily fright