At what metaphorical time on a 24-hour clock did humans arrive on Earth, if Earth began at midnight?

To understand why the correct answer is 11:59 on a metaphorical 24-hour clock, consider the timeline of Earth's history in relation to the development of human beings. Scientists estimate that Earth formed about 4.5 billion years ago. In this metaphorical representation, if Earth represents the entirety of its history on a 24-hour clock, humans, as a species, have only existed for a tiny fraction of that time.

When mapping this out on a 24-hour clock, the arrival of humans is positioned very close to the end of the day—specifically at 11:59 PM. This reflects the idea that modern humans (Homo sapiens) emerged only about 200,000 to 300,000 years ago, which is a minuscule period compared to the vast timeline of Earth's existence.

Therefore, placing human arrival at 11:59 signifies that we are very close to the end of this 24-hour period, illustrating how recent human existence is in the context of the Earth's long history. This metaphor effectively communicates the insignificance of our time on Earth compared to the planet's age.