Count Unique by dates

[Ronald]

Hi everbody,

I need to count by the name field, but I have sales on different dates to the same Customer.
I attach the example.

Carlos has sales to different clients (M1, M2, M3) but to M1 he has three sales in the same month, for the count it should only be considered as one sale; and one to M2 and one to M3, total Carlos three sales.
Sandra has two sales to the same M4 customer, and overall Sandra must be one sale.
Total Maria a sale

[GaryGiles]

I think you are looking for:

count(Distinct [Customer])