Is there a way to identify the 1st occurrence of a value in a new column in Power Query with respect to "date"? For example,

Date Value Unique
6/10/16 a 1
6/10/16 b 1
6/10/16 c 1
6/10/16 c 0
6/10/16 a 0
6/11/16 a 1

I have been able to create a new column that gives a count of the times the value is duplicated. But I can't get quite what I need.