Different count for Page Views for Historical Data

My guess is the problem lies with how you built your segments.... Using the wrong Segment Scope can result in pulling back data that you don't intend... in particular, using a Visitor scope segment will pull back ALL data for Visitors that match the criteria even once... 

For example, if I create the following segment:

Visitor

    Page equals home

Now let's look at a Visitor Journey:

• Dec 1
  • Page A
  • Page B
• Dec 5
  • Page C
  • Page A
  • Page D
• Dec 8
  • Home
  • Page A
  • Page E

When you looked at your Data on Dec 6, this visitor wouldn't appear, since up until this point, the visitor had not been to the "Home Page"

However, when you look at the data on Dec 9th, this visitor has now seen the home page... since your segment is Visitor scope, ALL the pages for this Visitor are now being returned, and will now show data in your reports for Dec 1 and 5.

If you segments are Visitor scope, you also are returning inflated data even if you were to look at Dec 8 in isolation, because Page A and Page E will be returned in your dataset as well...

You need to use a HIT scoped segment, to only return the URLs that match. You can still use your standard Visits and Unique Visitor metrics with such a segment...  the scope of the segment is about what data set you need to return.