Hi@arc012,
Based on the issue you mentioned, you want to filter the gallery based on the DatePicker selected date.
Could you please share more about your data source, is it a SP list or an Excel sheet?
I have a test using a SP list and the formula you provided goes well.
In an Excel sheet, a date column is Date and Time value, so you should format it when you make a filter.
I have a test on my side, please take a try as below:

Filter(
Table1,
If(
Campus = "Harvard",
"Harvard" = Campus
),
If(
DatePicker4.SelectedDate = Today(),
Text(
DateEntered,
DateTimeFormat.ShortDate
) = Text(
DatePicker4.SelectedDate,
DateTimeFormat.ShortDate
),
true
)
)
Please provide some screenshots about the error and your data source.
Best Regards,
Qi Qiao