How did mathematicians cope with the Covid lockdowns? COVIDIARY of Mathematicians is a new book published by the Mathematical Society Archimedes of Belgrade. It presents diaries from April 2020 of seven mathematicians in different parts of the world - Tiago Hirth (Lisbon), Guido Ramellini (Barcelona), James Tanton (Phoenix), Jovan Knezevic (Belgrade), Kiran Bacche (Bangalore), Sergio Belmonte (Altafulla), and Tijana Marković (Belgrade). Their diaries feature mathematics and (excellent) puzzles, mountainlettes, cooking and shopping, in the strangest of times. The book is beautifully produced, with copious colour pictures, and QR-codes taking the smartphone-equipped reader further afield. The editors Aleksandra Ravas and Dragana Stošić Milijković have done a wonderful job, providing full explanations in footnotes of any reference which might be unfamiliar to some readers. Solutions are provided to the puzzles! If you have the opportunity, I strongly recommend that you explore this book!