Lederman V. The May(a) Calendar

Waking up in the morning to discover that you are living your days in reverse is a far more serious matter than "Groundhog Day"! Sixth-grader Gleb Elizarov merely scratched the date "May 23" onto an ancient wall—and set off with a couple of his classmates first to May 22, and then to the 21st, 20th, 19th...

Gleb, who recently transferred to a new school, Yura Karasev, an awkward straight-A student, and Lena Zyuzina, bogged down by household chores, see a few perks in reliving the events of yesterday and the day before. You can retake a final exam, dodge a fight with a bully, or even spend all your pocket money on treats without a shred of guilt—because in the morning, the bills and coins will be right back in your wallet!
But the further the students get from May 23, the fainter the hope of returning to the future—and how can you erase an inscription that you won’t even make for another week? A field trip to an archaeological find supposedly belonging to the Mayan civilization became the start of an adventure for the three kids, one that no adult would ever believe. Or will someone finally believe them?
"The Mayan Calendar" is the debut novel by Victoria Lederman, which was an instant success (Special Prize at the V. Krapivin Competition, 2014). The author masterfully demonstrates how the characters of modern schoolchildren change under the pressure of a shared misfortune. The mystery of ancient tribes, a mistake that led to fateful events, conflicts with classmates, and a deep, lifelong friendship — it’s all in this book. In just a few years, "The Mayan Calendar" became a national bestseller; the book has been translated into six languages and masterfully adapted for the screen by director Victoria Fanasyutina.