how the date query works?

[David Belohrad]

Dear all,

could someone explain how to use date query? As of Oct 2012 Jani added
set of patches doing date query.

When I open in emacs search, and I type 'date:today', some output
appears, but not the one I would expect.

Interesting enough is, that if I press 'da' and then <tab>, it offers
date search.

Is there any kind of manual how to use it? I'm of course particularly
interested in 'today', 'yesterday', 'last week', 'last month' :)

thanks

david