🔍 Key Concepts

• Relationship between longitude difference and time difference (15° of longitude = 1 hour of time) • How to determine if another location is ahead or behind in time relative to Greenwich (0°) • Standard nautical time zone numbers (positive east, negative west)

💭 Think About

• From 0° to 54° E, is local time later or earlier than at Greenwich? By how many hours? • If it is 1200 (noon) at 54° E, what local time would it be at 0° and at 126° E, assuming standard time calculations? • Based on the longitude 54° E, what is the nearest standard time zone number, and is that zone written with a plus or minus sign?

✅ Before You Answer

• Compute the exact time difference between 54° E and Greenwich using 15° per hour, and decide if Greenwich is before or after noon. • Calculate the local time at 126° E using the same 15° per hour rule, starting from Greenwich time, not directly from 54° E. • Check the sign convention for time zones: longitudes east of Greenwich are usually assigned positive zone numbers, and west longitudes are negative. Verify whether a "-4" zone matches 54° E.