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: There is indeed an issue in "Einstein time" (Einstein's concept of time) because it takes the proper time of one observer as the fourth coordinate of all objects in the universe. We claim that there is a 4D vector "flow of time" for each object, which must be rotated in 4D Euclidean spacetime (ES) when transforming coordinates. SR and GR work well as approximations, but only if we consider objects on and close to Earth, where that vector is nearly the same. We replace Einstein time with Euclidean time, which takes the proper time of an object as its fourth coordinate. Unlike other models of Euclidean relativity (ER), we claim that reality is only formed by projecting ES to an observer's 3D space. We prove: The Lorentz factor is recovered in ER; acceleration relates to a 4D rotation; ER is compatible with quantum mechanics! We solve 13 mysteries, such as mc², gravitational time dilation, the Hubble constant, wave–particle duality, and entanglement. Four concepts (inflation/expansion of space, dark energy, non-locality) become redundant. We conclude: Occam's razor knocks out Einstein time.