Who Am I?

I lure you towards me,
I control your day.

You'd be all over the place if you didn't have me,
I'm a necessity, I daresay.

I can be chunked up, or one whole thing,
I tell you whom you need to email or whom to ring.

I know you're running out of milk and bread,
I know I'm the one thing you dread.

I'm emotionless and void of feelings.
So, stare at me all you want, or pretend I don't exist.

Who am I?
I'm none other than your to-do list!