I felt compelled to let you know that 1 A.D. (Anno Domini = latin for: year of our Lord = As in Christ Jesus) which for context was during the rule of the Roman Emperor Augustus back when the Roman Empire control most of Europe. Yes, this was in fact the classical period. Also current year is A.D. 2021 (also written as C.E.) meaning A.D. 1 was exactly 2020 years ago. The stone age ended 3,300 B.C. (Before Christ, also written B.C.E) B.C. dates progress backwards to the year 0 so bigger the number the further back you go.
Not trying to be mean. Just thought I'd let you know. I really like the concept of your game.