...agreed with Jerry that the date filtering seems to work with other data sets as seen in the following: ...so I wonder if the property type in your feature class definition is being seen as "string" or "date" type which would provide different filtering…

...was able to reproduce what you are seeing when using a non-RDBMS type property. Please attempt the following and let me know if you are able to filter your date properties as expected. Modify your date property to "dateticks" type as shown in…