Filtering a list with date ranges - xslt / advanced expressions on list filters possible?

Question

I've got a Sharepoint 2010 list that I'd like to filter with date-ranges. I'm doing something like

if END_DATE > [NOW - 1Week]
and END_DATE < [NOW + 1Week]
or PLAN_END > [NOW -1Week]
and PLAN_END < [NOW +1Week]

I will post the real code at the end of this post, but as it's just a bunch of code, it doesn't have too much of real relevance.

Now, when I use conditional formatting, I can use advanced expressions to make that happen (expression see below), but when using the list-view-webpart on a webpart-page - the additional formatting gets lost, which is intended behavior as I recall.

So I do not only have to hide the entries I dont want to see, I just do not have to select them in the first place (which makes more sense anyways). But is this possible via List-Filters? I know I can edit the code and write some XML-LINQ-Like expressions (forgive my terminology, really new to all this), but I can't find out how I would write the expression I need.

To sum it up: How can I FILTER a list with Date-Ranges?

And here the actual conditional formatting that I do (Hide all, where condition is not met)

not((ddwrt:DateTimeTick(ddwrt:GenDisplayName(string($thisNode/@Plan_x0020_Ende))) >= (ddwrt:DateTimeTick(ddwrt:Today())-(7*24*60*60*1000*10000))) 
    and (ddwrt:DateTimeTick(ddwrt:GenDisplayName(string($thisNode/@Plan_x0020_Ende))) <= (ddwrt:DateTimeTick(ddwrt:Today())+(7*24*60*60*1000*10000)))) 
and not((ddwrt:DateTimeTick(ddwrt:GenDisplayName(string($thisNode/@Ist_x0020_Ende))) >= (ddwrt:DateTimeTick(ddwrt:Today())-(7*24*60*60*1000*10000))) 
    and (ddwrt:DateTimeTick(ddwrt:GenDisplayName(string($thisNode/@Ist_x0020_Ende))) <= (ddwrt:DateTimeTick(ddwrt:Today())+(7*24*60*60*1000*10000))))

Answer 1

You can filter list by using CAML and DaysOffset attribute of the Today tag. This can be done even from GUI.

For example, this filter will narrow the shown items of a list view to those, which have Due date within a week from the current date:

(List Tools => List => Modify view on the contextual ribbon)

In terms of CAML, this will produce the following query:

<Query>
    <OrderBy>
        <FieldRef Name="ID"/>
    </OrderBy>
    <Where>
        <And>
            <Gt>
                <FieldRef Name="DueDate"/>
                <Value Type="DateTime">
                    <Today OffsetDays="-7"/>
                </Value>
            </Gt>
            <Lt>
                <FieldRef Name="DueDate"/>
                <Value Type="DateTime">
                    <Today OffsetDays="7"/>
                </Value>
            </Lt>
        </And>
    </Where>
</Query>

And btw, cannot resist mentioning, that the XSLT filtering approach is very expensive in case of resources (especially if there are many items in the list), and gives up the list paging. Personally, I would never ever use it in any case...