Send Date range as parameter in SAP Crystal Report

I have a formula created on SAP 11 for generating Report, but need to fetch according to StartDate and EndDate.

Below is my formula 

If {?districtid}<>0 Then
 {district_master.districtid} = {?districtid}
Else
 True
and
if {?zoneid}<>0 Then
 {zone_master.zoneid} = {?zoneid}
Else
 True

and
{school_master.reg_date} >= totext({?fromdt}) and
{school_master.reg_date} <= totext({?todt})

As you can see above there are 4 fields as districtid, zoneid, fromdt, todt.

This is not matching records. How the date field is being matched in SAP?