What are ETA, ETD, ATA, and ATD in Logistics? What Do They Do?

Companies engaged in import and export frequently use terms such as ETD, ETA, ATA, and ATD in both air and ocean freight transportation. These internationally recognized concepts for supply chain management are used for accurate date and time planning. In this article, we will examine the meanings of these terms, why they are important, and the factors affecting these dates.

What is ETA?

ETA, or estimated time of arrival, is a term frequently used worldwide to indicate the arrival time. Its abbreviation stands for estimated time of arrival. In the shipping and logistics industry, it is used to estimate when the shipment will arrive at its destination port.

For a vessel, container, or package in transit, the estimated time of arrival (ETA) can help the recipient track their shipment without having to call the shipping office. Concurrently, operation teams can use this data to optimize delivery schedules and improve predictability.

How is ETA Calculated?

Many factors are considered when calculating ETA. These include:

• Distance between point of origin and destination

• Average speed of the vessel

• Number of port calls

• Climate and weather conditions

• Time required for refueling

• Port traffic and congestion

• Unforeseen emergencies

Taking the relevant factors into account, you can calculate the estimated time of arrival with the following formula:

Estimated time of departure + Estimated transit time = Estimated time of arrival (ETA)

When providing ETAs, carriers must accurately estimate the time elapsed in processes. Here, real-time visibility through API integration and smart technology helps track vessels and provide precise port arrival times for the vessel or container.

What is ETD?

ETD stands for estimated time of departure. It is the date/time when the vessel or container is expected to depart from its port of origin. ETD is important as it provides information about the vessel's departure and informs recipients about the expected scheduled times for the arrival port.

Based on the estimated time of departure (ETD), carriers calculate the expected time of arrival (ETA) and estimated completion/delivery time as part of the shipment flow.

How is ETD Calculated?

The booking confirmation sent by the ocean carrier or freight forwarder usually includes an estimated time of departure. It is calculated by considering several factors such as:

• Vessel schedule

• Maintenance and refueling

• Weather conditions at both the origin port and various ports along the route

• Port congestion and equipment

• Labor and other factors

These elements affecting ETD are further classified by some businesses specializing in marine delay insurance. These include:

• Shore-side factors: Conditions such as labor unrest, traffic congestion, infrastructure difficulties, and transportation issues at ports.

• Vessel-related factors: Factors such as weather delays and vessel mechanical breakdowns.

Calculating the estimated time of departure is highly important as it helps recipients with berth planning, tug arrangement, shore permission, departure schedule planning, and other operations.

What is ATA?

ATA stands for actual time of arrival. It is the exact time that a specific mode of transportation reaches its intended destination. Its abbreviation stands for actual time of arrival.

Unlike the estimated time of arrival (ETA), the ATA is the actual time when planes, trains, buses, ships, or other modes of transport arrive, which may be later or earlier than the ETA due to standard delays.

ATA is when a vehicle arrives at a destination, but it can still vary by company or industry. For flights, ATA may be when the aircraft reaches its gate rather than when it lands, and for an Uber ride, it may be when the driver arrives at the pickup area.

What is ATD?

ATD stands for actual time of departure. It is the time when an aircraft actually takes off. Its abbreviation stands for actual time of departure. In logistics, ATD can also refer to the point in time when a shipment is sent. Its counterpart is ATA, the concept describing when the shipment arrives.

While the Estimated Time of Departure (ETD) is a known factor, the Actual Time of Departure can only be specified once the shipment is on its way. Comparing ETD and ATD helps recognize any delay in delivery.

Why are ETA, ETD, ATA, and ATD Terms Important in Logistics?

By correctly determining and processing each of these dates, it becomes possible to manage the supply chain with minimal friction. Every single date is of great importance, especially for port management, the smooth progress of transportation, and the timely receipt of products by importing companies.

ETA and ETD, which are the estimated arrival and departure dates, are crucial for port management. Through these dates, port authorities:

• Allocate resources efficiently.

• Minimize vessel waiting times.

• Control port congestion.

Thus, time is saved by preventing unnecessary truck queues and waiting fees at ports.

Accurately determining these dates has a great impact not only on port management but also on the progress of the transportation process. With the rapid increase in the world's population, the supply of many products has become more critical than usual.

Vessel capacities and the number of voyages have increased. For this reason, ETA and ETD, the estimated arrival and departure dates, have started to affect the entire process in this sense. A vessel arriving later or earlier than specified can negatively affect other voyages and disrupt the entire process.

Finally, determining these dates as accurately as possible is also highly important for importing companies. Importing companies plan their product supply according to the ETA information provided to them.

Most import companies act by anticipating extensions in transit times. However, some delays negatively affect the supply time of the product. For instance, a product transported via a transshipment service may wait at the transshipment port for one or two weeks depending on the congestion at that port.

This delay can result in heavy penalties or loss of customers for the importing company. It is highly critical for importing companies that the estimated arrivals provided by carrier companies are realistic.

What are the factors that negatively affect ETA and ETD?

Of course, since these dates are estimates, they can deviate from actual information from time to time under the influence of certain situations. Situations that negatively affect this information can be exemplified as follows:

• Bad weather conditions

• Strikes

• Congestion at the port of destination

• Congestion at the port of origin

• Vessel breakdowns or accidents

• War or pirate attacks

We recommend you read our relevant blog content for things to consider when exporting via ocean freight and the key points of this mode of transportation.