ddoc missing alias definition

[Andrej Mitrovic]

Take a look at: http://www.digitalmars.com/d/2.0/phobos/std_date.html

On the first few lines there's:
alias d_time;

Where's the type that d_time aliases to? I've tried using the default style.ddoc from http://www.digitalmars.com/d/2.0/ddoc.html, but I still can't print out the name of the aliased type. The same thing happens with typedefs.

Is this a bug?