Fix off by one date errors on CT reports

The utc conversion was causing it to cut off hours at the end of the
day as enddate would end up being a datetime object with 10pm today.
This change seems really incorrect. `startdate_display` returns the string formatted date that we display to the user, `startdate_utc` returns the utc datetime that marks the start of the day in the the particular timezone. Why would you want to be comparing with the date string rather than the actual time that that day starts in that timezone?