The |heures filter (since SPIP 1.2, SPIP 1.2.1) displays the hours portion of the date to which it is applied.[(#DATE|heures)]
The hour returned varies from 00 to 24.
If the date to which the filter is applied does not contain any time information, e.g. ([(#VAL{2009-10-24}|heures)]), the filter will simply return (zero).