Ferrite material plays an important role in modern microwave components such as isolator, circulator and phase shifter. Also, they provide some agility to externally tune devices by adjusting a DC magnetic field which modifies the constitutive parameters. However, ferrite medium is complex and elaborated modelling procedures are required to carry out full-wave electromagnetic simulation. A general TLM (Transmission-Line Matrix) procedure is proposed to model those media in time-domain. It accounts for effects such as non-homogeneous DC magnetization and arbitrary magnetization state by inserting a physical causal model and coupling static simulation to accurately account for the demagnetization field which depends also on the ferrite sample geometry.