I don't know if I should warp the thread like this or if the question was a joke, but this is my take.

A date is when two people make a specific plan for a specific day (date) during which they will attempt to push their relationship forward in a romantic direction.
A bad date is when, mid-date, either one or both parties come to the conclusion that the relationship will never become romatic, that the romance was a bad idea, or that the date caused the relationship to weaken instead of strengthen.

But because a date is about strengthening, maintaining or beginning a romantic relationship, anything can be a date, whether it's a night out with a group of friends or a spontaneous meeting at Taco bell. Whatever brings a couple closer together.