Usage of Zulu time in shipping industry & its significance

The international shipping industry works in a traditionally channelised way. Traders have to share a common platform of trading terms, communication and time zone! Yes, captains of all the ships sailing across different sea routes in the world refer to a similar time zone, called the Zulu time. It is the time reference to Zero Meridian. It was commonly referred to as GMT (Greenwich Mean Time) until 1972. Today, most of us ordinarily use it as a term for UCT (Universal Coordinated Time) or UTC (Universal Time Coordinated). The BIPM (Bureau International des Poids et Mesures) maintains this coordinated time scale.

The vessels facilitate international trade work as per the Zulu time and the “Z time”. It is vital to understand its usage and significance in this codependent industry where a trader cannot operate without the consent of his partner.

Usage of Zulu Time In Shipping Industry

The Zulu or Z time zone is a part of the nautical time. It is split into several intervals that last for one hour. This time is accounted for every 15-degree change that occurs in the longitudinal coordinate of a ship. Since Great Britain was the first and most influential maritime power in the world when the world started to identify the concepts of longitudes and latitudes, it was discovered as the Prime Meridian.

Today, the usage of this time zone is relevant in explaining:

  • The time of shipment: The exporters need to specify the time when they will load the cargo in the shipping vessel. Also, in some cases, explain the time difference between loading and departure of the vessel.
  • Time of arrival at the destination port: The importers need to know the time of delivery as per the Z time, so they can make the arrangements for import customs.
  • Door to door delivery: In the case of this shipping agreement, the time of every movement of the cargo has to be recorded and conveyed to the importer or the third party authorised for receiving the cargo.

Significance of Zulu or Z Time

The Zulu time is expressed or read in specific terms of a 24-hour clock based on the time divisions of the Gregorian Calendar. The world shipping organisations and trade communities agreed to use this time after considering a few facts.

  • There was a time when scientists believed that the earth takes around 24 hours to rotate on its axis. Later, shreds of evidence proved that it is not always the same for all parts of the country. For example, Antarctica and Greenland ice sheets do not have a legal standard time. So, it is not practically possible to modify time in these places if it does not offer a common solution.
  • The Z or Zulu Zone runs from 7°30′W to 7°30′E longitude. This period was desired as UT1 or Greenwich Mean Time from 1st January 1972.
  • In maritime usage, as noted by the international shipping industry, the GMT period has maintained its historical meaning successfully, as explained in UT1. Although the captains of cruises and some other ships have the right to switch to their preferred clock once the ship has entered a different time zone, most of them choose the Z time only!

The purpose of channelising trade through a common time zone is to maintain uniformity in the operations. Explaining and converting one country’s time reference to another while discussing the shipping details can be a hectic task! Since importers and exporters already have a lot on the table to handle, it is best to simplify the terms of communication. Therefore, every trader should do his part of understanding the Z time and its differences with the other time zones in use.