Unique Entries with Criteria

Hi,

I am still having issues with a problem with counting unique entries with criteria.

I am trying to count the number of days in a month a supplier has a visited.

I want a formula that allows me to see how different dates XXX has visited in each month. So in a particular month somone may visit 5 times but only on 2 different dates. The formula would then bring up the answer 2. Whereas if someone visited 5 times, but on 4 different dates, the formula would bring up the answer 4.

The data is continuous, so each new day more rows will be added. I need a formula that does not need to be adjusted daily as I add in new rows with new visits.

I would prefer not to use pivot tables.

Please can someone help! I have attached an excel with the data and a table to the right which I need to fill out.

Thanks,

Leopold2000