Answer:
Though not a plant, has leaves. Though not a beast, has spine. Though many wouldn't need this thing, It's more valuable than wine.
What is weightless but it needs two person to hold it?
When the day after tomorrow is yesterday. Today will be as far from Wednesday. As today was from Wednesday. When the day before yesterday was tomorrow. What is the day after this day?
Twigs and spheres and poles and plates. Join and bind to reason make.
Always old, sometimes new. Never sad, sometimes blue. Never empty, sometimes full. Never pushes, always pulls.
My days are numbered.
Difficult
Animal
Easy
Food
Funny
Kids
Logic
What am I?