A person who goes around the world from east to west ( the same direction as Magellan 's voyage ) would lose one hour for every 15 ° of longitude crossed , and would lose 24 hours for one circuit of the globe from east to west if they did not compensate by adding 24 hours when they crossed the IDL .
If someone travels around the globe in an airplane from east to west ( the same direction as Magellan ) , they should subtract one hour for every 15 ° of longitude crossed , losing 24 hours for one circuit of the globe ; but 24 hours are added when crossing the International Date Line ( from east to west ) .