This fatwā considers that, as a result of traveling internationally, people may miss Friday (i.e., depart on a Thursday and arrive on a Saturday). Pursuant to the Ḥanbalī school of thought, however, all persons aboard ships and aircraft are to perform Friday congregational prayers.
These prayers are only to be performed on Friday: If, as a result of traveling, a person has two Fridays, he or she is to perform the prayer on the first of those two Fridays. If it is that there is no Friday, however, the person is to estimate the appropriate time at which to pray.