In a client's master data, there are three predefined fields used to store date values. Each serves a distinct purpose:

Database field: reg_datetime

The reg_datetime field is updated with every registration via an interface. These registrations are treated as new sign-ups, which is why the date is overwritten. However, if a user re-registers via the newsletter management page—for example, to subscribe to an additional newsletter—no update occurs, since the user is already known to the system.

Database field: tsCreated

Introduced in November 2015, the tsCreated field stores the original creation date of a data record. It is only populated for users who registered after its introduction, meaning those who were not previously present in the system.

Database field: tsLastUpdate

The tsLastUpdate field records the date of the most recent change to a data record. It is updated by all processes that modify master data, including:

• Registrations via interfaces
• Unsubscriptions
• Bounces
• Negative list imports
• Automatic domain blacklist imports
• API processes
• Manual and automated imports