ETA, ETD, ATA, and ATD are the trip clock: two estimates (arrival and departure) and two facts (actual arrival and departure). In ocean shipping they anchor the vessel or container to a port; on the Mexico–U.S. corridor the same language governs drayage and last mile without diluting the maritime search intent.
- ETA · ETD · ATA · ATD
- 4 terms
- estimate ↔ actual (out & in)
- 2 pairs
- clear point: port, gate, or DC
- 1 anchor
- milestone pilot on one corridor
- 6–8 wks
Cluster: shipment · demurrage · control tower · logistics monitoring · multimodal TMS.
What ETA, ETD, ATA, and ATD mean (table)
The four acronyms come from operational shipping English. In plain terms:
ETA
English: Estimated Time of Arrival
Spanish: Hora estimada de llegada
What it measures: When arrival is expected at the defined point (port, terminal, DC, customer)
ETD
English: Estimated Time of Departure
Spanish: Hora estimada de salida
What it measures: When departure is expected from origin (berth, yard, dock)
ATA
English: Actual Time of Arrival
Spanish: Hora real de llegada
What it measures: When it actually arrived (berth, gate-in, destination geofence)
ATD
English: Actual Time of Departure
Spanish: Hora real de salida
What it measures: When it actually left (departure, gate-out, yard exit)
Golden rule: name the point. “ETA Manzanillo” is not “ETA Guadalajara DC”. Without an anchor, WhatsApp invents a parallel clock. Related: what a shipment is.
Why they matter for ports, appointments, demurrage, and inventory
These timestamps are not carrier jargon: they move money, dock space, and stock promised to the customer.
Port / terminal
What the clock decides: Berth, cranes, gate, and container free time
If the milestone lies: Queues, burned appointments, demurrage
Dock / DC appointments
What the clock decides: Unload window vs operable ETA
If the milestone lies: Wait time, truck detention, redelivery
Inventory / plant
What the clock decides: In-transit available vs floor available
If the milestone lies: Surprise stockout or overstock
Accounts payable / dispute
What the clock decides: ATA/ATD + gate as evidence
If the milestone lies: You pay demurrage or detention with no defense
In 2026 the Manzanillo–inland corridor still shows a familiar pattern: the vessel can berth “on time” and drayage still slips due to port access, roadworks, or burned SIP/EDD appointments. The line portal’s ETA does not forgive free time if your box does not leave. Calibrate free time with your contract or the carrier’s published tariff; do not invent days. See demurrage and detention / dwell.
Estimate vs actual: ETA↔ATA and ETD↔ATD compliance
The value is not memorizing acronyms: it is measuring the gap and typing the cause.
ETD–ATD
Business question: Did we leave when we promised?
Healthy signal: ATD ≈ ETD (same window)
Failure signal: Recurring late ATD: loading, docs, origin customs, berth slot
ETA–ATA
Business question: Did we arrive when we promised?
Healthy signal: ATA inside window / tolerance
Failure signal: Late ATA: weather, congestion, diversion, prior call
ATD–ETA
Business question: Is the transit plan still credible?
Healthy signal: ETA recalculates when ATD confirms
Failure signal: Frozen ETA after late ATD = cascading broken promise
ATA–next milestone
Business question: Does free time / appointment / inventory start?
Healthy signal: Typed ATA triggers plan B
Failure signal: ATA only in chat: demurrage and inventory blind
Complement with OTD (on-time delivery): OTD looks at the customer promise; ETA↔ATA looks at the leg’s truth. You need both.
What moves ETA (weather, congestion, customs, access)
ETA is not a magic TMS number: it is an estimate that degrades if nobody updates it with facts.
Weather / swell / canal
Where it hits: Ocean transit and berthing
How to type the exception: Service delay (carrier) · new published ETA
Port or yard congestion
Where it hits: Anchorage, berth, yard
How to type the exception: Berth wait / yard dwell · operable ATA impact
Customs clearance / pedimento
Where it hits: Container release
How to type the exception: Docs / duties / exam · fake ETA to DC
Access / SIP-EDD slots / roadworks
Where it hits: Gate and drayage (e.g. Manzanillo inland)
How to type the exception: Burned appointment · access queue · late yard ATD
Drayage / chassis capacity
Where it hits: Dray to DC or border
How to type the exception: No equipment / no appointment · multimodal ETA breaks
Public 2026 sources (Maersk corridor notices, T21 coverage on Manzanillo access) underline the same point: the bottleneck is often after berthing. That is why your tower needs port ATA and a recalculated ETA to the door. See customs clearance.
How to use them in the control tower, TMS, and exceptions
A TMS that only shows vessel ETA with no alert owner is decoration. The tower turns the clock into action.
Operable clock
From estimate to exception
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Anchor the point
Minimum protocol for a Mexico–U.S. shipper:
- Every milestone has a source (carrier portal, GPS, geofence, app, typed message) and lives under the trip ID.
- If the ETA↔ATA or ETD↔ATD gap crosses a threshold, someone acts in minutes (typical tower meta: first useful action), not “someone saw it on the map”.
- WhatsApp can notify; it is not the system of record. The notice must land as a milestone in the TMS/file. See control tower and logistics monitoring.
Mexico–U.S.: one clock across ocean, drayage, and last mile
The query is maritime; real corridor ops almost never end at the berth. The same vocabulary prevents one Excel per mode.
Ocean
Clock anchor: Vessel / container / port
Typical document: Booking · bill of lading (B/L)
Closing milestone: ATD sail · ATA berth / gate
Drayage
Clock anchor: Tractor + container
Typical document: Carta Porte + CFDI (Mexico)
Closing milestone: Yard ATD · ETA/ATA DC or border
Long-haul / crossing
Clock anchor: Trip / unit
Typical document: Carta Porte · POD
Closing milestone: ETA window · geofence ATA · POD
Air (when used)
Clock anchor: Flight / AWB
Typical document: Air waybill (AWB)
Closing milestone: Flight ETD/ATD · airport ETA/ATA
OCL is multimodal (road, ocean connection, air): one thread of milestones and exceptions. It does not replace the ocean carrier; it stops each mode living in a different chat. Guide: Mexico–U.S. multimodal TMS · multimodal visibility and documentation.
Checklist: time milestones that close the trip
Use this on a one-corridor pilot (port, DC or port, and border) before buying “another tracking screen”.
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Point anchored per milestone
Step 1
What OCL executes with milestones under one trip ID
The wedge is not “another acronym list”: it is finished work. OCL Cargo is an autonomous TMS with computer-use agents (they operate screens and portals) that concentrate ETA/ETD/ATA/ATD milestones, status, and evidence (GPS, POD) under the same trip ID; WhatsApp or the app can capture typed milestones without becoming a parallel spreadsheet.
Agents + your team
Milestones that reach a decision
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Detalle del paso · 01
Capture milestone
No day-one TMS replacement required. Typical pilot 6–8 weeks on one corridor; recovery pattern 5–7% when auditing 100% of the pilot flow; order of magnitude ~$50 MXN per shipment when scope fits. Humans on exception judgment, not on refreshing the map. Context: fake digitization and the human bridge.
Related reading
- What a shipment is · road vs ocean document anchors
- Demurrage · free time and gate evidence
- Chassis and multimodal detention
- Real-time logistics monitoring
- Control tower
- Mexico–U.S. multimodal TMS
- OTD (on-time delivery)
- POD (proof of delivery)
Key takeaways5 points
- ETA/ETD plan; ATA/ATD prove. Without the estimate↔actual pair you cannot measure compliance or dispute demurrage.
- Name the timestamp point: berth, gate-in, DC, or customer door. An ETA with no anchor is rumor.
- On Mexico–U.S. the same clock must cross vessel, clearance, drayage, and truck; otherwise inventory and appointments lie.
- Healthy tower: typed milestones under the trip ID, exception owner, and actionable notice to dock/accounts payable.
- OCL concentrates milestones + evidence (WhatsApp/app, GPS, POD) without a day-one TMS migration; 6–8 week pilot.
Does your ETA live in the portal and your ATA in WhatsApp?
Frequently asked questions
ETA and ETD are estimates (arrival and departure). ATA and ATD are facts (actual arrival and departure). In ocean shipping they anchor the vessel/container to a port; the same clock language applies to truck and air on multimodal trips.
No. ETA is the estimated arrival at the point you defined (port, terminal, DC). The appointment is the slot agreed with the receiver. You can have a solid ETA and still burn the appointment if access, customs, or drayage fail. See unload zone and logistics monitoring.
The carrier publishes service ETA/ETD. Your tower must own the operable ETA of the container through plant or DC: clearance, drayage, crossing, and last mile. If you only copy the line’s portal, you measure the ship, not the order.
ATA at the terminal starts the equipment free-time clock. If the box does not leave on time, demurrage appears. If it leaves but the empty does not return on time, detention/chassis appears. Without ATD/ATA tied to the trip ID, accounts payable disputes blind. Guides: demurrage and chassis/detention.
Yes as milestone language: estimated/actual departure and arrival. The anchor changes (tractor, flight, vessel) and so do documents (Carta Porte, AWB, bill of lading). On the Mexico–U.S. corridor, keep one multimodal clock. See multimodal TMS.
Two gaps: ATD − ETD (departure) and ATA − ETA (arrival), by leg with typed cause. Complement with OTD (on-time delivery) and % of actual milestones tied to the trip ID before pay.
OCL is an autonomous multimodal TMS: agents concentrate ETA/ETD/ATA/ATD and evidence (GPS, POD) under one trip ID; your team decides exceptions. Coexists with your TMS; typical pilot 6–8 weeks; 5–7% pattern when auditing 100%; ~$50 MXN per shipment order of magnitude when scope fits.