is the column DATE a datetime field and are the parameters datetime as well? That is the first thing I would check.
Just as a question, why are you having a SQL command select the data for your report?
The reason I ask, is that I have always used the SQL command to populate parameters for Crystal. I think that was the original intent, and while it probably works, it may have quirks as I don't think this is the designed function.
If you want to write your own SQL, create a view or stored proc and pass the parameters to that.
I don't mean to preach or push you to write a report in a certain way, it just that are quite a few people who write reports this way, and then they run into issues as Crystal treats SQL commands in a way different than the report writers 'thought' it should work.
With that in mind, if I was writing this for SQL, well, I wouldn't but syntax that is confusing me, is the single quotes around the date parameters and the double quotes around the fields. Do you have a field called DATE? Try running your query in your database software (like SQL Server) and see if it is working. For SS, you would enter the ' around the date, but that is because you are typing it. If you were comparing it to another datetime field you wouldn't and this may or may not affect the SQL command when the parameter is coming from Crystal...depends on what / how you are entering the data and Crystal is passing it
HTH