You know you're having a bad day when - Everyone is laughing but you.
You know you're having a bad day when - You call your wife and tell her that you would like to eat out tonight, and when you get home, there is a sandwich on the front porch.
You know you're having a bad day when - Your income tax refund check bounces.
You know you're having a bad day when you notice that the bird singing outside your window is a vulture.
You know you're having a bad day when you try to pick up the clothes you wore home from the party last night, but there aren't any.
You know you're having a bad day when you wake up to the calming sound of running water and then remember that you recently bought a waterbed.
You know you're having a bad day when your ex-wife is your blind date.
You know you're having a bad day when your twin sister forgets your birthday.