Until it is measured, not known. Yet how you miss it when it has gone. What is it?

I am Huge on Sunday and Saturday.
I am small from Tuesday to Thursday.
I do not exist on Monday and Friday.
Who am I?

You can win me and lose me but never buy me
You can not eat me and never want to part with me
I can make you cry or bring you joy
I am not a machine and definitely not a toy
You keep me but i am not forever just yours
You might find me in a case or on a shelf next to a vase
I am hard and i am tall if you bump me i am sure to fall
I am made of different materials and am at many events
If your lucky and fight hard I might be yours
What am I ?

I am a word of 12 alphabets.

* Alphabets 12, 4, 7, 2, 5 : Eastern beast of burden
* Alphabets 1, 8, 10, 9 are street made famous by Sinclair Lewis.
* Alphabets 11, 3, 6 are past.

On whole it means a person suffering from delusions of greatness.

What Is it ?

I welcome the day with a show of light, I stealthily came here in the night. I bathe the earthy stuff at dawn, But by noon, alas! I'm gone.

A finger goes in me. You fiddle with me when you're bored. The best man always has me first. What am I?

I’m tall when I’m young, and I’m short when I’m old. What am I?

Take one out and scratch my head, I am now black but once was red. What am I?

No matter how little or how much you use me, you change me every month. What am I?

My thunder comes before lightning.
My lightning comes before my rain.
My rain dries up all the land it touches.

Who am I?