What is the origin of the idiom "bright and early" and when to use it?

The exact origin of the idiom "bright and early" is unclear, but it has been in use since at least the early 19th century. The phrase combines the words "bright" and "early" to convey the idea of starting a task or activity at the first light of day, when the sky is brightening. It is often employed in everyday conversations, informal writing, and even in more formal or professional settings.