The whole process targets the so-called “Day of Operation”, which is the day a particular flight takes place. The day of operation is part of the operations control phase, which is a 3-day window starting two days before and including the day of operation, if the day of operation is 5th of September then the time horizon of operations control is 3rd of September, 00:00 UTC to 5th of September, 24:00 UTC. The main concerns during this phase are enabling the safe and efficient conduction of flights as well as keeping changes to schedules to an absolute minimum.