使用datepart（日）汇总一个不同的计数

Here is my issue. This is a tanning salon and we have recently added spa services. Clients use to tan just time in a day so counting distinct clients by employee was pretty easy. Now They tan/spa more then one time in a day and see different staff on any given day. I am trying to SUM the dinstinct client count by day into one number. Here is the query. I hope this make sense. Please forgive me as first time I have posted? Here is my issue. This is a tanning salon and w