postgis - GeoServer where clause filter

I use PostGIS, GeoServer, and OpenLayers for GIS development.

I simply reach from GeoServer to PostGIS table or view and show it with OpenLayers, but I need some filtering operation on my spatial data. For example, I have historical spatial data and filter them to start_date and finish_date like:

select ....... 
from ......
where date between :start_date and :finish_date

The problem is start_date and finish_date are dynamic. User changes them from web my open layer web project.

How can I do it using GeoServer?