A solid-state continuous time crystal (CTC) with an internal clock has been experimentally realized using driven-dissipative exciton-polariton condensates. The system is based on microcavity polaritons, which are quasiparticles formed by the strong coupling of excitons and photons in a semiconductor microcavity. These polaritons exhibit rich many-body quantum behavior, including spontaneous breaking of time translation symmetry, which is a hallmark of time crystals. The CTC is formed from an incoherent particle bath that is continuously driven by a non-resonant optical laser. As the power of the laser increases, the system undergoes a series of phase transitions. Initially, the system exhibits Larmor precession of pseudo-spins, a signature of continuous time crystals. As the power increases further, the frequency of the precession locks to self-sustained coherent phonons, leading to a stabilized time crystal. At higher powers, the system exhibits period doubling, where the frequency of the time crystal is doubled by phonons, indicating a discrete time crystal with continuous excitation. The system demonstrates period doubling in response to an internal mechanical clock, which is self-induced by the polariton fluid. This mechanical clock stabilizes and locks the frequency of the time crystal, acting as an internal clock. The results establish microcavity polaritons as a platform for studying time-broken symmetry in non-Hermitian systems. Theoretical models describe the dynamics of the polariton condensate coupled to a dynamical reservoir and a mechanical clock. The system exhibits continuous time crystalline phases that are tuned by the particle number. The dynamics are governed by the interplay of non-resonant driving, coupling to excitons in a dynamical reservoir, cavity dissipation, and interactions in a many-body quantum polariton system. The experimental results show that the system exhibits a sequence of phase transitions, including the formation of synchronized condensates, symmetry-breaking pitchfork bifurcations, and the emergence of limit cycles and period doubling. These transitions are consistent with the theoretical model and demonstrate the robustness of the time crystal behavior against variations in physical parameters. The findings pave the way for exploring time crystals in open many-body quantum systems and could serve as a testbed for dynamical gauge theories, with applications in quantum simulators for quantum electrodynamics and quantum chromodynamics models.A solid-state continuous time crystal (CTC) with an internal clock has been experimentally realized using driven-dissipative exciton-polariton condensates. The system is based on microcavity polaritons, which are quasiparticles formed by the strong coupling of excitons and photons in a semiconductor microcavity. These polaritons exhibit rich many-body quantum behavior, including spontaneous breaking of time translation symmetry, which is a hallmark of time crystals. The CTC is formed from an incoherent particle bath that is continuously driven by a non-resonant optical laser. As the power of the laser increases, the system undergoes a series of phase transitions. Initially, the system exhibits Larmor precession of pseudo-spins, a signature of continuous time crystals. As the power increases further, the frequency of the precession locks to self-sustained coherent phonons, leading to a stabilized time crystal. At higher powers, the system exhibits period doubling, where the frequency of the time crystal is doubled by phonons, indicating a discrete time crystal with continuous excitation. The system demonstrates period doubling in response to an internal mechanical clock, which is self-induced by the polariton fluid. This mechanical clock stabilizes and locks the frequency of the time crystal, acting as an internal clock. The results establish microcavity polaritons as a platform for studying time-broken symmetry in non-Hermitian systems. Theoretical models describe the dynamics of the polariton condensate coupled to a dynamical reservoir and a mechanical clock. The system exhibits continuous time crystalline phases that are tuned by the particle number. The dynamics are governed by the interplay of non-resonant driving, coupling to excitons in a dynamical reservoir, cavity dissipation, and interactions in a many-body quantum polariton system. The experimental results show that the system exhibits a sequence of phase transitions, including the formation of synchronized condensates, symmetry-breaking pitchfork bifurcations, and the emergence of limit cycles and period doubling. These transitions are consistent with the theoretical model and demonstrate the robustness of the time crystal behavior against variations in physical parameters. The findings pave the way for exploring time crystals in open many-body quantum systems and could serve as a testbed for dynamical gauge theories, with applications in quantum simulators for quantum electrodynamics and quantum chromodynamics models.