In ancient Greek culture, Kairos was the personification of the concept of the opportune moment. Unlike Chronos, the personification of time as a linear, measurable progression, Kairos represented the fleeting and unpredictable moments in which important decisions and actions could be taken.

Kairos was typically depicted as a young man with wings on his feet and a lock of hair hanging down over his forehead. He carried a set of scales, representing the balance and impartiality needed to make wise decisions in the moment.

The idea of Kairos was important in Greek philosophy and rhetoric, as it emphasized the importance of seizing the right moment to make a persuasive argument or take decisive action. This concept has continued to be influential in Western culture, with the notion of "seizing the moment" or "carpe diem" still resonating today.