Time Converter Mystery Cache

NOTE: This cache is 1 of 16 associated with the Ol' Salty Dog's Maritime Mixer cache series.

Find your way to the physical cache container at the coordinates revealed by solving the puzzle below. In the physical cache container, attached to the log, you will find a "puzzle piece" that will get you one step closer to finding Ol' Salty Dog's Maritime Mixer.

Standard time is the local time in a country or region. Daylight Saving Time (DST) is the practice of setting the clocks forward, generally, one hour from standard time during the summer months, and back again in the fall, in order to make better use of natural daylight. More than 60% of the countries in the world use standard time all year. The remaining countries use DST during the summer months.

Before the late nineteenth century, time keeping was essentially a local phenomenon. Each town would set their clocks according to the motions of the Sun. Noon was defined as the time when the Sun reached its maximum altitude above the horizon. Cities and towns would assign a clockmaker to calibrate a town clock to these solar motions. This town clock would then represent "official" time and the citizens would set their watches and clocks accordingly.

The latter half of the nineteenth century was time of increased movement of humans. In the United States and Canada, large numbers of people were moving west and settlements in these areas began expanding rapidly. To support these new settlements, railroads moved people and resources between the various cities and towns. However, because of the nature of how local time was kept, the railroads experienced major problems in constructing timetables for the various stops. Timetables could only become more efficient if the towns and cities adopted some type of standard method of keeping time.

In 1878, Canadian Sir Sanford Fleming suggested a system of worldwide time zones that would simplify the keeping of time across the Earth. Fleming proposed that the globe be divided into 24 time zones, each 15 degrees of longitude in width. Since the world rotates once every 24 hours on its axis and there are 360 degrees of longitude, each hour of Earth rotation represents 15 degrees of longitude.

Railroad companies in Canada and the United States began using Fleming's time zones in 1883. In 1884, an International Prime Meridian Conference was held in Washington D.C. to adopt the standardize method of time keeping and determined the location of the Prime Meridian. Conference members agreed that the longitude of Greenwich, England would become zero degrees longitude and established the 24 time zones relative to the Prime Meridian. It was also proposed that the measurement of time on the Earth would be made relative to the astronomical measurements at the Royal Observatory at Greenwich. This time standard was called Greenwich Mean Time (GMT).

Today, many nations operate on variations of the time zones suggested by Sir Fleming. The image below shows how the various time zones are currently represented on the Earth. In this system, time in the various zones is measured relative the Coordinated Universal Time (UTC) standard at the Prime Meridian. National boundaries and political matters can also influence the shape of the time zone boundaries. For example, China uses a single time zone (eight hours ahead of Coordinated Universal Time) instead of five different time zones.

Each time zone is represented by a number that indicates how many hours the zone is earlier (negative sign) or later (positive sign) than the Coordinated Universal Time standard. For example, Tokyo, Japan uses (GMT +9) Japan Standard Time which is 9 hours ahead of UTC; and the US Territory of Midway Atoll uses (GMT-11) Standard Time which is 11 hours behind UTC.

Utilize your sleuthing skills and identify the Standard Time Zone in which each of the below listed coastal cities (annotated as A through J) is located. The zone number (or last digit) will provide the needed number for each missing decimal minute digit of this puzzle cache's coordinates.