In the last decade, metasurfaces opened new and exciting possibilities to realise properties beyond those available in natural materials. However, I identify entirely unexplored means to manipulate the electromagnetic properties of these surfaces, and I plan to investigate them in this project. More specifically, we know that by engineering shapes of the meta-atoms it is possible to couple electric and magnetic properties creating, for example, bianisotropic metasurfaces. Nevertheless, the effects produced by temporal variations of meta-atom parameters are still unknown. How time-modulation changes the phenomena of bianisotropy, and perhaps even more importantly, how such "dynamic" metasurfaces can be applied to the design of practical devices? In this project, I plan to answer these questions by studying time modulations of metasurfaces with engineered spatial dispersion, with the goal to exploit all possible degrees of freedom for controlling wave propagation.