NOAA and Average/Extreme pages stop at 30 days

I’ve noticed over the past 6 or 7 months that the daily updates to the NOAA and average/extreme reports that are automatically generated will not include the last day of a 31 day month. Both my December and January reports, when viewed the morning of the first of Jan/Feb show only days 1-30. I can force them to generate the full month by going to view/averages and extremes, and clicking the 31st of the preceeding month. Is it possible the reports are being automatically generated before the data for the 31st is saved to the appropriate data file?