In Orchard.Fields, Tokens\FieldTokens.cs, method Evaluate(dynamic context) :

context.For<DateTimeField>("DateTimeField")

            .Token("Date", (Func<DateTimeField, object>)(field => field.DateTime))
            .Chain("Date", "Date", (Func<DateTimeField, object>)(field => field.DateTime))
            ;

is repeated twice.

but the "Time" token specified in Describe is not returned (and "Date" won't return only the Date as announced.