The quantum zeno effect slows down the quantum system’s time evolution under frequent measurements. This paper aims to study this quantum effect by introducing the definition of time based on an irreversible thermodynamic analysis of quantum systems. Consequently, the quantum zeno effect requires (i) high values of the electromagnetic entropy generation rate related to the spontaneously down-converted light and (ii) a decrease in the quantum system’s entropy value. So, the quantum zeno effect is a quantum process related to the interaction between a quantum system and the electromagnetic waves of the measurement device, causing a quantum thermodynamic stationary state. Last, the fundamental role of irreversibility emerges.