Two 0.93(Na${}_{0.5}$Bi${}_{0.5})$TiO₃–0.07BaTiO₃ ceramics were sintered for 2$$h and 3 h, respectively, by a conventional solid reaction method. The ceramic sintered for 2$$h showed a normal ferroelectric hysteresis loop and paramagnetic behavior, while the ceramic sintered for 3$$h showed a pinched ferroelectric hysteresis loop, weak ferromagnetism, and enhanced magnetoelectric coupling. The origins of the sintering time-related multiferroic properties are discussed in detail. The work offers a new way to induce multiferroicity in ceramics by tuning sintering time.