Histogram doesn't reflect special calendars?

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Bob
2010-01-21
2013-05-15
  • Bob
    Bob
    2010-01-21

    I set up a calendar for 7-days-a-week work and set up my project to use this calendar.  It all works as expected until I bring up the histogram, and the black line for availability for every resource  is locked at zero for Saturdays and Sundays.  Is it a bug, or am I missing the point somehow?