The US has asked vessels requesting to cross the Strait of Hormuz to sail during two variable time windows for the purpose of securing passage, and not only at night, amid Iranian attacks on ships. This was reported by the Financial Times. From notices sent to maritime traffic advisors, it appears the change in time windows occurred around the beginning of September. One email stated that vessels are not required to move at the specified time, but "it is recommended for optimal support." Another email noted that "passage during hours of darkness has not proven itself to be the safest time of day."