Timezones are a confusing topic for a global marketplace like Amazon. For example, a customer in New York places an order on March 11, 2021, at 1 AM (EST), but it is March 10, 2021, at 10 PM (PST) @ Amazon HQ in Seattle. When did the order occur? March 11th or March 10th?
Another wrinkle is that Amazon Selling Partner API and Amazon Advertising API default to using a Coordinated Universal Time (UTC) standard in their systems. In our example above, the timestamp of the order would be March 11th, 2021, at 8 AM!
Seller Central User and Amazon Advertising Interface
So, where does a chunk of the confusion arise? Amazon Seller Central. The Seller Central interface displays information in Pacific timezone (PST). However, Amazon stores information in its systems using UTC.
Per Amazon Selling Partner and Ads:
“Amazon formats date and time-related data similar to the RFC 3339 standard, which defines a subset profile of ISO 8601 for use in Internet protocols and standards. This section will clarify how you should format and use date and time data in Amazon”
Why does Amazon use UTC?
Why use UTC? Per the RFC 3339 spec;
Because the daylight saving rules for local time zones are so convoluted and can change based on local law at unpredictable times, true interoperability is best achieved by using Coordinated Universal Time (UTC). This specification does not cater to local time zone rules.
UTC’s use avoids local, regional, or national variations for time zones, including daylight savings time (DST). This is why the conversion of a timestamp should always occur when displayed. For Seller Central, they convert UTC to display it as PST.
Most data analytics tools like Tableau, Looker, DataStudio, and Quicksight…allow you to convert a timestamp from UTC to EST, PST, or whatever your preference.
How timezones impact your understanding of the data
As discussed, you will observe time shifts in Amazon user interfaces for North America, Europe, and the Far East Regions because they choose to display a timestamp in a specific timezone. However, regardless of how Amazon (or you) decide to display the data, it does not change the system timestamp is always UTC.
Let’s say you have a transaction with an order date of
2021-03-16T06:32:16.50 or March 16th, 2020, 6:32 AM. Amazon then displays this time in the Seller Central interface as
2021-03-15T23:32:16.50 or March 15, 2020, 11:32 PM.
These values are both correct, except one is a base (UTC), and the other is derived (PST). What do we mean by derived? It means that you convert the UTC timestamp to any other timezone. Amazon chooses to use PST for display in North America or CET in Europe.
Coordinated Universal Time is 8 hours ahead of Pacific Standard Time or 7 hours ahead of Pacific Daylight Time. As a result, looking at an interface based on PST and data provided in UTC can result in significant perceived shift orders, returns, fulfillment...dates.
Remember that the UTC default from Amazon systems is stored exactly as they provide it in your data lake or warehouse. Understanding timezones may help you explain why an order may have one date in one place and different data in another.