DateTime value has additional hour after insert I developed a Windows Service (with a fixed culture of "de-DE") in C#. This service is getting data from an API and copies it over to a Navision Database.

My problem is following: After I've copied the data, every DateTime value got an additional hour. So if the DateTime value from API was 13:25:00, in the Navision database it is now 14:25:00.

When retrieving the DateTime value from API it is of kind "Unspecified".

To insert it into the Navision database I'm doing a simple
INSERT INTO [TABLE] (..., [Date_Time], ...) VALUES (..., [DATETIME VALUE], ...).

This just happens on customer side. In my test environment I can confirm that the same DateTime value from the source is inserted into the database.

I used the Database Creation Script provided by the customer to create the database in my test environment.

I cannot see all sources of failure, because I'm not yet so deep into this.
This is an application issue more than a database issue.

Navision treats datetime entries as UTC, and is adding the hour in its display (assuming your local timezone is UTC+1).

I have run into this myself since I work with Navision. If you have a client application, you can look at displayed datetime for a record and compare it to what you see by querying the table.