January 1, 45 BCE
The Julian calendar takes effect
Caesar proposes a calendar reform in 46 BCE, advised by the astronomer Sosigenes of Alexandria, and it takes effect on 1 January 45. To realign it with the seasons, 46 BCE is lengthened to 445 days.
January 1, 45 BCE
Caesar proposes a calendar reform in 46 BCE, advised by the astronomer Sosigenes of Alexandria, and it takes effect on 1 January 45. To realign it with the seasons, 46 BCE is lengthened to 445 days.