How to Handle International Campaign Data and Time Zones

Why time zone mismatches create double counting

Amazon Ads reports often use the marketplace's local time zone. If you merge a US report ending at midnight Eastern with a UK report ending at midnight GMT, the shared hours do not line up. A click recorded at 10 p.m. in London may fall on a different date in New York. When both files are combined without adjustment, that click can appear twice or disappear from a daily total.

This is not just a formatting issue. Double counting spend makes ROAS look worse, while missing records hide real performance problems.

A working method for standardizing before the merge

A practical approach is to pick one reference time zone, such as UTC or your company's home office time zone, and convert every report timestamp before merging. You can do this in a spreadsheet by standardizing the date and hour fields, or use a reporting tool that normalizes across marketplaces. Amazon Ads Dashboard by Todoza, for example, is built to consolidate reports into a single cross-account view without stitching together raw files.

• Convert all date and time values to the same time zone.
• Define a consistent day boundary, such as midnight in the reference zone.
• Reconcile total spend before and after conversion to catch shifted records.

When this matters

Time zone standardization matters most when you are managing campaigns across marketplaces with a shared budget, or when you need to report daily spend to a client or finance team. It also matters when you schedule daily imports from multiple accounts and expect the totals to match Amazon's console.

If most of your campaigns run in one country, you can usually use that local time zone. Once you add a second region, a written rule prevents recurring cleanup work.