running a report with date parameters

[susanna123]

I have a crystal report that is scheduled to run on a daily basis

The report has 2 parameters, a start and end date.

Since the report is to be run on a daily basis, by selecting a start date and an end date would only give me the data
between and including those dates, no matter if it is run for today, tomorrow or the next day.

Is there a way to change the start and end date parameter values to "null" so that it runs with different data for the next day.

 

[susanna123]

report is not based on any store procedure. It just utilizes tables.

 

[RoMarcus]

What is your logical date range for each day? excample...Last two days?

 

[susanna123]

my start date parameter and end date parameters are both of type: date.

I am trying to set a default value of 01/01/1900 so that if the default value is selected, it will display all records otherwise display records based on the selected date.

(if {?@Start Date} = date(01/01/1900) then
true
else

{@Instance Start Time} >= {?@Start Date}) and
(

(if {?@End Date} = date(01/01/1900) then
true
else

{@Instance End Time} = (datetime(9999,9,9,9,9,9)) or
{@Instance End Time} <= {?@End Date})
)

Thks.