I use a report viewer in a perspective view and I want the user to be able to select for which date he wants to see the data in the report from the perspective view.
Here's an example from one of my meter data reports. I have a date time input for the start and end date time parameters. There is a button that will set the start and end times to the parameters but you could just directly bind them also.
In my 2nd screenshot you can see my two parameters "start" and "end", i created them by clicking the plus icon up by the parameters area in the top left. They are referenced in the query by the question marks.
In the perspective view you can bind the date time inputs to the report viewer's "start" and "end" parameters or assign their values on a button event like i did. Hopefully that answers your question, if not let me know what specific part you are having trouble with.