Umbraco 6.1.6 installation with version 2.0.1 of DateFolders installed.

Using the Publish At feature of Umbraco to publish a DateFolders enabled document to publish at a future date/time results in the document being published but not being written to the cache and therefore unavailable.

I installed the source code and ran through the debugger and found that the following line in the Document_AfterSave method was generating an exception for a null value because the current HttpContext was null:

var page = HttpContext.Current.CurrentHandler as Page;

Replacing that line with the following code (DISCLAIMER: NOT EXHAUSTIVELY TESTED) allowed the Publish At feature to work properly:

HttpContext context = HttpContext.Current;
Page page = null;
if(context != null)
   page = HttpContext.Current.CurrentHandler as Page;