The reason is that the newly defined DateTime class takes precedence over the System.DateTime.

Solution: 
The class that is inherited should be:

System.Web.Mvc.WebViewPage <System.DateTime>

NOT

System.Web.Mvc.WebViewPage<DateTime>

Hope you will look into this.

What's the repro scenario?

davidebbo wrote:

What's the repro scenario?

To reproduce, add the a DateTime View:

Views/Shared/EditorTemplates/DateTime.cshtml

The scenario is that one is overriding the default DateTime template; pretty common

But what is the content of this template? Or are you saying that you get this error even if your DateTime.cshtml is an empty file?

My guess is that the problem is in your template itself. e.g. you might have something like '@model DateTime?' that needs to be '@model System.DateTime?' instead.

Awesome!

I will try using the full type name, thanks