Answer:
What goes up and down but never moves?
What time is spelled the same forwards and backwards?
What cleans as it gets dirty only to get clean the more you use it?
Big as a saucepan, deep as a cup, Even a river can't fill it up. What is it
What has been around for millions of years but is never more than a month old?
Black we are and much admired. Many seek us if they are tired. We tire the horse, and comfort man, and turn White when we've fulfilled your plan.