Enter the AIRAC cycle to choose an AIRAC data set to use. The proper AIRAC cycle is picked by default based on the departure time of the flight. You can specify an AIRAC offset in the Airline Code Parameters screens.
The AIRAC Cycle Buffer field on the Airline Code Parameters FOMS screen tells the system when to cut over to the next AIRAC cycle, if the field is blank the default cutover is 0000z. You can also override the AIRAC cycle to be used for a given flight plan calculation.
With this process, the time gap between creating initial difference files and processing them on your system is eliminated. Instead a new data environment is created for the new AIRAC cycle and the live data is copied to it to have the updates applied.
This gives you more time to check disabled/changed routes in advance of the upcoming AIRAC cycle, but the system automatically attempts to apply user route changes to the next cycle in the hopes of eliminating AIRAC-based route maintenance. During the AIRAC cycle changeover, Dispatchers can use the current AIRAC cycle and plan flights that would fall under the new AIRAC cycle.