Time Zonesand the International Date Line

Strange things happen to time when you travel, because the earth is divided into twenty-four time zones, one hour apart.You can have days with more or fewer than twenty-four hours, and weeks with more or fewer than seven days.

If you make a five-day trip across the Atlantic Ocean, Your ship enters a different time zone every day.As you enter each zone, the time changes one hour.Traveling west, you set your clock back；traveling east, you set it ahead.Each day of your trip has either twenty-five or twenty-three hours.

If you travel by ship across the Pacific, you cross the international date line.By agreement, this is the point where a new day begins.When you cross the line, you change your calendar one full day, backward¹ or forward.Traveling east, today becomes yesterday；traveling west, it is tomorrow!

你在旅行中，在时间方面会有一些希奇的事情发生，因为地球分成24个时区，每时区间相隔一小时。在你度过的日子中，可能有多于或少于24小时的；在你度过的星期中，也可能有多于或少于7天的。

假如你进行为期5天越过大西洋的旅行，你的船天天都进入一个不同的时区，每进入一个时区，时间便改变1小时。朝西旅行，你把时钟往后拨；往东旅行，你把时钟向前拨。你旅行中的每一天要么是25小时，要么是23小时。

假如你乘船越过太平洋，你将穿过国际日期变更线。按协定，这是新的一天开始的地方。穿过这条线时，你要在日历上往后或往前更动一整天。朝东旅行，今天变成昨天；往西旅行，今天就是明天。