That SQL will make a pretty good guess, but it's not perfect. Here's the operative quote -
Having an accurate report is going to depend on straightening up the data entry situation.I also made the assumption that, if the dates are the same between different plantlocation records, then any one of them will do. If instead you want the record with the lowest or highest ID, then you can change "First(tP1.ID)" to "Min(tP1.ID)" or "Max(tP1.ID)", respectively.
If you have what you need, please mark the thread "solved". Top of page, under "thread tools". If you come up with other questions later, it's better to start a new thread.