What is the origin of the idiom "about time" and when to use it?

The origin of the idiom "about time" can be traced back to the Middle English period, where the word "about" was used to mean "concerning" or "regarding." The use of "about" in this manner can be seen in expressions like "about that matter" or "about this issue." In this phrase, the emphasis is on the passage of time and the feeling of it being an appropriate or overdue moment for a particular event or action. It is commonly used in informal conversations, casual writing, and even in more formal settings.