Do you need to do more than just display the Sundays, such as group data and perform aggregates, etc.?
I understand your nervousness about large posting when new to a a product, however technical information is soliticted, as opposed to text descriptions:
Database/connectivity
Example data
Expected output
Since you don't know Crystal's technical terms, lay it out as a mini-spec.
Do you need dates for all Sundays between the dates in the database? This is a common concern wherein you have 3 weeks worth od data, but the requirement states show all weeks in the period.
Also your requirements might be more clearly identified by stating that you want Crystal to group the dates by week, with Sunday as the first date, and display the Sunday date regardless of whether the date matches one from your data.
-k