🔍 Key Concepts

• Time = Distance ÷ Speed to find travel time in hours and days • How to convert between Zone Time (ZT) and Greenwich Mean Time (GMT/UT) using Zone Descriptions (ZD) • Crossing the Pacific from East longitude to West longitude and how that affects the date when you change time zones and cross the 180° meridian (IDL)

💭 Think About

• First, compute how long the voyage will take at 14 knots using the given distance. About how many days and extra hours is that? • Once you have the elapsed time, add it to the departure ZT at Yokohama. Then think carefully about which direction you are going (E to W) and how the local time zone changes as you move toward Seattle. • When you convert from the time at Greenwich back to local time at Seattle, what is Seattle’s approximate Zone Description (ZD) in July, and how will that affect the clock time and the calendar date?

✅ Before You Answer

• Verify your distance ÷ speed calculation and convert the decimal hours to hours and minutes correctly. • Keep track of the date separately from the clock time when adding the voyage duration — don’t lose a day when carrying hours past 24. • Double-check the sign and value of the ZD for Yokohama (-9) and the ZD for Seattle in July, and be sure you handle the International Date Line crossing in the correct direction.