Q: filter for dates that fall in between start date and end date? I have a datetime column which I want to filter on two start date and end date parameters. however if the startd ate and end date are the same value no rows are returned.
ua.actiondate < '2013-10-08' and ua.actiondate  > '2013-10-08'

ua.actiondate between '2013-10-08' and '2013-10-08'

example values of my actionDate column
2013-10-08 12:30:17.000
2013-10-08 12:30:17.000
2013-10-08 12:31:56.000
2013-10-08 12:32:22.000
2013-10-08 12:35:35.000
2013-10-08 12:35:40.000
2013-10-08 12:35:40.000
2013-10-08 12:36:03.000
2013-10-08 12:36:44.000
2013-10-08 12:36:44.000
2013-10-08 12:36:54.000

as you can see the actionDate column is a date time object but the parameters are only dates. 

A: Since 2013-10-08 12:35:40.000 is greater than 2013-10-08 you have to use something like this
where ua.actiondate >= '2013-10-08' and ua.actiondate  < '2013-10-09'


A: You should always use an open-ended date range and never use between.
WHERE ua.actiondate >= @startdate AND ua.actiondate < DATEADD(DAY, 1, @enddate);

This assumes @startdate and @enddate are always passed as dates with no time. If there is time involved (e.g. the app might pass now()) then you can round off using:
WHERE ua.actiondate >= CONVERT(DATE, @startdate)
  AND ua.actiondate <  CONVERT(DATE, DATEADD(DAY, 1, @enddate));

