At 0915 zone time on 7 April you depart San Francisco, LAT 37° 48.5' N, LONG 122° 24.0' W (ZD +8). You are bound for Kobe, LAT 34° 40.0' N, LONG 135° 12.0' E, and you estimate your speed of advance at 17 knots. The distance is 4,819 miles. What is your estimated zone time of arrival at Kobe?
• Time = Distance ÷ Speed to find total steaming time in hours • How to convert between zone time (ZT) and Greenwich Mean Time (GMT/UT) using the zone description (ZD) • How to cross the International Date Line and adjust date and time zone when going from west longitude to east longitude
• First, compute how many hours it will take to travel 4,819 miles at 17 knots, then convert any decimal hours into hours and minutes. • Convert the San Francisco departure time from local zone time (ZD +8) to GMT. Then add the steaming time to find GMT at arrival. • From the GMT at arrival, apply Kobe’s approximate time zone (ZD) and remember you are crossing the Pacific and the International Date Line—decide whether to add or subtract a day when changing from W to E longitudes.
• Be precise with the calculation: Time (hours) = 4,819 ÷ 17, and convert the decimal correctly to minutes. • Confirm that San Francisco’s zone description is +8 and determine Kobe’s correct ZD based on 135°E (how many 15° time zones from the prime meridian?). • After adjusting from GMT to Kobe ZT, double‑check the calendar date and make sure the hour and date change are consistent with crossing the International Date Line.
No comments yet
Be the first to share your thoughts!