Yea the date is a date/time format.
Don't think that's what the question was. A field that contains only date values is date/time format. A field that contains date and time is also date/time format. This 9/1/17 is cut off at 9/1/17 00:00:00 when time is not provided. I have had to deal with this before - not that difficult actually. If the field contains time, one way to handle this is to use the DateAdd function and add the appropriate number of minutes (or seconds) to the date. Such as BETWEEN 09/15/2017 AND DateAdd("n",1440,#09/21/2017#). 1440 (minutes) may not be the value that works best for you, but in that example it would push the date to midnight of the next day.
The more we hear silence, the more we begin to think about our value in this universe.
Paraphrase of Professor Brian Cox.