Data warehouse - Segment on Daily unique

Hi,

I want to create a report over a year, with granularity per day, where I can see Daily unique visitors on my different Pages broken down by Mobile device type. So far I can do everything except find the metric Daily unique visitor. I don't want the visitors be unique for the whole time frame, just per day. 

Can't find this Daily Unique Visitor metric or how to create it. Is it possible some how?

Appreciate any help // Br Daniel