1. Create a new constituent export
2. Include a query if desired
3. Go to the output tab
4. Select the following fields to export:
Constituent Information, Name
Summary Information, Gifts, Total Number of Gifts
First Gift, Gift Date and filter on the desired date range.
5. Click Export Now.

This will show the total number of gifts given for the date range. Only donors who gave their first gift in this date range will have a date in the first gift date field.