Heh. I wonder how many readers know what "cron" referrs to.
For those scratching their heads at the reference, "cron" is a the name of a process under the UNIX operating system, that as the name may suggest, deals with time related things - specifically scheduling of processes to run in the system. Usually used to kick off regular things like maintenance processes on a system that may run every minute, x times per hour, hours per day etc up to specific days in a year. Quite useful for regular thing you may want to run at certain times to a schedule.
The idea
@Cloud9 is suggesting here I think is perhaps a process in the backend running say every minute that checks any flights due to depart in 24h, and for any flight scheduled in 24h to then put them kick off associated processes eg open OLCI.