The Age of the Universe by Thierry Blancpain
Cosmic Calendar is a calendar conceptualized by Carl Sagan where all the 13.8 billion year lifetime of the Universe was scaled to fit on a one year calendar. Big Bang of course, occurred in the beginning of the year, the sun formed at 1 September, first life ( prokaryotes-simple cells) appeared at 21 of September, land plants at 20 of December, mammals at 26 of December, and primitive humans only at 22:24 of 31 December.
Something good to have in mind in this monday Earth Day.
A good thought for a monday morning.