Answer:
You fill it and it empties, A metaphor for plenty, Depending on what half you see, It's either full or empty
Its days are numbered.
Old Mcdonald had this
If it is absolute, it will corrupt absolutely.
It's been around for millions of years, but it's no more than a month old. What is it?
It can be cracked, It can be made, It can be told, it can be played. What is it?
Easy
Animal
Difficult
Food
Funny
Kids
Logic
What am I?