Carl Sagan's Cosmic Calendar, in which the entire 13.75 billion-year history of the universe is scaled down to a single year. At this scale, the Earth formed in August, life arose in September, and the first land plants appeared in mid-December. Apes did not appear until the very last day of the year. The first humans show up in the last six minutes and civilization in the final 30 seconds.
Carl Sagan's Cosmic Calendar - The cosmic calendar compresses the local history of the universe into a single year. If the universe began on January 1st it was not until May that the Milky Way formed. Other planetary systems may have appeared in June, July and August, but our Sun and Earth not until mid-September. Life arose soon after. We humans appear on the cosmic calendar so recently that our recorded history occupies only the last few seconds of the last minute of December 31st.