I think I can help but the description of the problem is not enough to give an exact advise.
But if you have a data in Postgresql in some table and they are points with a location (there is a geometry column) and also there is an attribute with a timestamp (or something like this).. Import PostGIS service to catalog, add the underlying table with points as a layer to the map, check projections, etc (basic stuff), then in properties dialog of the layer there is "Query" page where an advanced user may specify a query using basic SQL-like operands and sentences as "TIMESTAMP_FIELD BETWEEN 'some date' AND 'some date' " .. Something like this, again.
In the end it's just a Filter object being set to Layer object that causes loading the data and rendering it on the map accordingly given filtering criteria.
If you need custom UI, configure development environment with UDIG SDK and implement some custom UI view or dialog where users may manage filtering criteria that becomes a Filter object being passed to Layer and... see above:)