Date and time parameter In msrs report
I wouldn't worry about setting the time component.  Just write your query like this instead:

WHERE SomeColumn &gt;= @StartDate
  AND SomeColumn &lt; DATEADD(Day, 1, @EndDate)


You have @EndDate = Today() which by default does not have a time component (or rather it's already 00:00:00).  Adding a whole day to that gets you tomorrow at midnight.  So the query above asks for any data on or after @StartDate but no later than tomorrow at midnight.

If you're querying a SQL 2K8+ instance you can further do this to be sure you're not erroneously using a time component:

WHERE SomeColumn &gt;= CONVERT(Date, @StartDate)
  AND SomeColumn &lt; CONVERT(Date, DATEADD(Day, 1, @EndDate))