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

The idiom "be early days" is an idiomatic expression that suggests it is still the beginning or early stages of a process, endeavor, or situation. It conveys the idea that there is still a significant amount of time, progress, or development needed before reaching a more advanced or conclusive stage. The phrase is often used to express caution, patience, or a lack of certainty regarding the ultimate outcome or result.