Timezones are a confusing topic when it comes to 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. What when did the order occur? March 11th or March 10th?
Another wrinkle is that Amazon defaults to using a standard called Coordinated Universal Time (UTC) in its systems. In our example above the timestamp of the order would be March 11th, 2021 at 8 AM!
Seller Central User Interface
So where does a chunk of the confusion arise? Amazon Seller Central. The Seller Central interface displays information in the Pacific timezone (PST). However, Amazon stores information in its systems using UTC.
“Amazon Marketplace Web Service (Amazon MWS) 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 just how you should format and use date and time data in Amazon MWS.”
See this doc for Amazon's use of RFC 3339
Why does Amazon use UTC?
UTC’s use avoids local, regional, or national variations for timezones, including daylight savings time (DST). This is why conversion of a timestamp should always occur when it is displayed. For Seller Central, they convert UTC to display it as PST.
Most data analytics tools like Tableau, Looker, DataStudio, Quicksight…allow you to convert a timestamp from UTC to EST, PST, or whatever your preference may be.
How timezones impact your understanding of the data
As we 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 fact 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 of your choosing. Amazon chooses to use PST for display in North America or CET in Europe.
Remember that the UTC default from Amazon systems is stored exactly as they provide it your data lake or warehouse. Understanding timezones may help you explain why an order my have one date in one place and a different data in another.