Working with dates

Luster

Hi all I am a newbee to Pascal programming and have spent the entire day trying to convert a string to a valid data that I can later use to subtract another date from to discover the number of days between the two dates. Can some one pls pls help me. Thank you.

I started with this code to try to convert the first date entered in string format to a date that can be used in a calulation:

program TryDate;

Var
date1: TDateTime;
thedate:string;

Begin
Writeln ('Enter date');
Readln (thedate);
date1:=StrToDate (thedate);
Writeln ('The date is ',date1);
end.


The program's basic structure can be seen here:

Begin
Writeln ('Enter customer last name');
readln (clname);
Writeln ('Enter customer first name');
readln (cfname);
Writeln ('Enter Dvd Title');
readln (dvdtit);
Writeln ('Enter Due Date');
readln (dued);
Writeln ('Enter Actual Date Returned');
readln (adret);
daysover:=adret-dued;
readln;
end.

I am expected to expand the program further but was trying to get this small part to work before trying the other components.

Simple instructions and examples or possible solutions will be greatly appreciated.