Not exactly sure how you are wanting to do this but in general you can do this in 4 basic ways.
1. Alter your select statement to Exclude the data so it won't be in the report at all
2. Create a formula field to Sum on e.g. if condition then 1 else 0
3. Use variables that have If-then statements to include/exclude in a count
4. Use a Running Total (RT) with a formula in the Evaluate section to only count the records you want.
I am guessing that when you indicate that a date is appearing even though "there is no data" you mean a particular field in that row is either NULL or empty.