By the turn of the millennia, it became clear that circadian clocks tick in every cell of the body, not only in the brain. These clocks have to be synchronized to the external environment and between each other. This is generally done through a variety of inputs that reset, or entrain, the clocks. Which signals participate in the resetting of peripheral clocks? Do all peripheral clocks respond the same, or is there tissue-specificity ( Manella et al., Proc. Natl. Acad. Sci. USA, 2020; Manella et al., Nature Metabolism, 2021)? Do different peripheral tissues communicate time information between each other, and how? In the lab, we employ in vivo mouse models, organotypic tissue explants, and cell culture approaches to shed light on these fundamental questions. We also developed Circa-SCOPE, a novel method for the high-throughput testing of multiple resetting cues in parallel, using live single-cell fluorescence microscopy (Manella et al., Nature Communications, 2021) and identified non-additivity and gold change detection (Manella et al., Proc. Natl. Acad. Sci. USA, 2022 ).