# Now on to special examples: date is the first property that has to
# be used in a particular way. If you send a query like the following,
# you might happen to receive not only the message sent at that particular
# date and time, but all the ones sent the very same day. This is due to
# IMAP server inner working and cannot be changed on the IMAP side. 
# However, the desired result can be obtained just by uncommenting the 
# FILTER constraint.

PREFIX xsd: <http://www.w3.org/2001/XMLSchema#>
prefix email: <http://davide.eynard.it/rdf/email#>

select ?date ?subject where
{
	?x email:subject 	?subject .
	?x email:date		?date .
	?x email:date		"2007-07-06T22:48:18Z"^^xsd:dateTime .
	#FILTER (xsd:dateTime(?date) = "2007-07-06T22:48:18Z"^^xsd:dateTime) .
}

# NOTE that the same result is obtained also if you comment the line 
# above the FILTER constraint. However, if you have logging enabled
# for INFO messages you'll notice that the number of downloaded messages 
# changes much. In fact, when you specify a date a search is done on the
# IMAP server and the results are "pre-filtered", so performance is better.
# A more specific example on this in the next query