Why does my library show as Released on Jan 1, 1900?

Question

Why does my library show as Released on Jan 1, 1900?

Answer

If a .NET or .NET Core library (package) is unlisted from NuGet, the published date is set to 1900 in the API. This is called out in the NuGet documentation - Package Metadata, NuGet API:

On nuget.org, the published value is set to year 1900 when the package is unlisted.

The published field is used by Contrast for the Released date.  As such, in this instance functionality is as designed.

More information can be found at - Deleting NuGet Packages from nuget.org .

Contrast has logic to ensure that an unlisted version is not shown as the latest version. However, we cannot correct these release dates as there is no way of knowing what the original release date was after the package is unlisted.

Example:

In the Contrast UI, the library has a Released date of Jan 1, 1900:

In NuGet, you will see the following warning:

The owner has unlisted this package. This could mean that the package is deprecated, has security vulnerabilities or shouldn't be used anymore.