The plane wave diffraction by an acute-angled wedge located on a perfect electric conducting plane is studied in the frequency and time domains. Only a TMz polarization is explicitly considered in the manuscript since the case of a TEz polarization can be solved in a similar way. At first, the uniform asymptotic physical optics approach is used to obtain the diffraction coefficients in the framework of the uniform geometrical theory of diffraction. The analytical procedure allows one to obtain closed form expressions that are easy to handle and provide reliable results from the engineering viewpoint. The time domain diffraction coefficients are successively determined by applying the inverse Laplace transform to the frequency domain counterparts. The effectiveness of the proposed solutions is proved by means of numerical tests and comparisons with full-wave numerical techniques.