Final answer:
Data Transfer (DT) timestamps for impression and click files use Coordinated Universal Time (UTC), which serves as a standard reference time across the globe.
Step-by-step explanation:
The time zone used in Data Transfer (DT) timestamps for impression and click files is not based on the user's local time or the advertiser's time zone, nor is it Eastern Time (ET). Instead, these timestamps typically utilize Coordinated Universal Time (UTC). UTC provides a uniform time reference for global operations, like military activities, international broadcasts, air traffic control, and also in fields such as data transfer. UTC is a 24-hour system that replaces the need for AM and PM designations, facilitating coordination across different time zones without confusion. For example, when you see a time marked in UTC, it represents the same moment regardless of where someone is in the world. Utilizing this time standard helps eliminate the issues that can arise due to the many different local time zones in use globally.