Counts are off by one in many random cases, particularly near the week/month/year boundaries.
Problem stems from at least odd date computations for figuring when the week/month/year begins and ends, and then improper comparisions with each blog entry.
There may be more problems (uninvestigated) with GetDaysWithEntries() and GetEntriesForDay().
Fixed code attached. File is based from 2.0.7226.0