The book satisfies some curiosities about our calendar and some events that marked the beginning of year counting. Does our calendar, known as the Gregorian calendar, have a year zero? In December of year zero, how old was Christ? And had Herod already died before year zero, as some historians claim? How can we prove that our calendar is correct? The book confirms the validity of the current calendar based on an unprecedented chronological research conducted in 2016 when it was possible to demonstrate synchronicity with 6 other events, including 1 annual, 2 specific, and 3 millennial ones: astronomical in March, historical in 70 AD, biblical in 2 BC, Christian holidays in June and December, and the Jewish circumcision ceremony! The narrative is fictional, but the chronological research is real. The narrative tells, in a light and enjoyable manner, the adventure of Aline, Enrico, and Júlia, high school students, who, with the help of their mentor Gaspen, successfully complete their mission to present the results of their research at the end of the school year. Their research proves that, at the end of year zero of the current calendar, Christ was one year old. They had crucial support from researcher João Carlos, who paved the way.