Answer:
I am the place where yesterday is always before today. What am I?
When young, I am sweet in the sun. When middle-aged, I make you gay. When old, I am valued more than ever. What am I?
They are many and one, they wave and they drum, used to cover a stare, they go with you everywhere.
When it comes to me you go on red and stop on green.
If you lose me, you may cause people around you to lose me too. What am I?
No matter how little or how much you use me, you change me every month.