In the Oracle database the date/time is stored in a string.
I already have created an SQL expression to sort it ascending as followed:
TO_TIMESTAMP("EVENTS"."EVENTCREATED" , 'DD-MM-YYYY HH24:MI:SS')

No I need to make an option so I can select a start and end date.
for example if I want to select dates between 15-09-2011 25-09-2011.

I already tried to create a parameter for this, but when I select the the time frame, I get everything between 15 & 25-09-2011 but also records from 01-10 and further.

Now I've got two questions:
Do I need to make an expression of parameter field from the string as the "TO_TIMESTAMP"?
How can I create the option, so I can select the start and ending date?

Thank you in advance

yes, you would need 2 parameters, one for start and the other for stop.