If a location is 45 degrees west, how do you determine the local time?

To determine the local time at a location that is 45 degrees west, you need to consider the difference in time zones relative to Greenwich Mean Time (GMT), which is considered the starting point at 0 degrees longitude. Each degree of longitude corresponds to 4 minutes of time difference from GMT, as there are 24 hours in a full 360-degree rotation of the Earth.

At 45 degrees west, you multiply 45 by 4 minutes to find the total time difference:

45 degrees × 4 minutes = 180 minutes, or 3 hours.

Since this location is west of GMT, the local time will be behind GMT. Therefore, to determine the local time, you subtract 3 hours from GMT. This indicates that the answer is indeed to subtract 3 hours to adjust for the time difference based on longitude.

Understanding time zones is crucial for navigation and scheduling, as the Earth rotates, creating differences in local time across various longitudinal lines.