Hi zblankenship,
Maybe check the Update property of the card housing the datepicker in the form - usually PowerApps detects the date format from the source and puts the datepicker constructs into the form for you - but these tend to include minutes and seconds, which you don't need. It then constructs a datetime format from all three dropdowns used to collect date and time and then saves that back to the source - it usually looks something like this;
DataCard Update Property (on the card, not the dropdown itself):
DateValue1.SelectedDate + Time(Value(HourValue1.Selected.Value), Value(MinuteValue1.Selected.Value), 0)
The dateformat of the date dropdown can be shortdate, but it's the formula above that gets applied and saved along with the minutes and seconds, even if they're zero.
If this is the case, you should be able to just remove the minutes and seconds from the update formula, leaving the Update property as;
DateValue1.SelectedDate
Hope this helps,
RT