Today's concept of time traces back to Albert Einstein's theories of special (SR) and general relativity (GR). In SR, uniformly moving clocks are slow with respect to my clocks. In GR, clocks in a more curved spacetime are slow with respect to my clocks. Many physicists anticipate that GR has an issue as it isn't compatible with quantum mechanics. Here we show: "Einstein time" (Einstein's concept of time) has an issue because it takes the proper time of an observer as the fourth coordinate of all objects in the universe. We replace Einstein time with "Euclidean time", which takes the proper time of an object as its fourth coordinate. SR and GR work very well as long as we describe the world on or close to Earth. Only then does time flow in one direction for all objects. To avoid the paradoxes that other models of Euclidean relativity (ER) run into, we claim that reality is formed by projecting Euclidean spacetime to an observer's 3D space. We prove: The Lorentz transformation is recovered as an approximation in ER; acceleration is related to a 4D rotation; ER is compatible with quantum mechanics. We solve 13 mysteries, such as time's arrow, mc², gravitational time dilation, Hubble's law, the Hubble constant, the wave–particle duality, and quantum entanglement. Four concepts of physics (cosmic inflation, expansion of space, dark energy, non-locality) turn out to be redundant. We conclude: As ER outperforms SR and GR, Occam's razor knocks out Einstein time.