Fatigue Prediction models are used as scheduling tools to manage risks associated with fatigue. They allow for proactive identification of possible hazards and the use of risk management tools to mitigate risks aspects of a Safety Management System (SMS). These tools provide ways for airlines to predetermine which flights and schedules may have more risk and allow operators to intervene and proactively reduce risk when possible. This process allows the operator to identify inherent risk built into flight schedules to maximize alertness. This adds another layer to the operators’ safety management systems. Current fatigue prediction models do not account for light/night effect on alertness levels. The effects of light on alertness have been well established and could be built into fatigue risk management systems. Recent research conducted by Brown et al., (2014) examined whether timed ocular light exposure could mitigate fatigue, reducing physiological, perceived and cognitive fatigue —to transform aviation alertness models . The availability of this information opens up a new range of possibilities, making it possible to “build” light/dark effect into crew alertness models and scheduling tools to improve aviation safety, crewmember health and manage risk.