I look at piwik's FAQ on the reconstruction statistics.
This is the URL address http://piwik.org/faq/how-to/#faq_59

My piwik statistics in September 2016, there have been problems, lost the monthly statistics.
Now time is October 12, 2016, I am ready to rebuild the September statistics.

I have deleted the data table piwik_archive_numeric_2016_09 and piwik_archive_blob_2016_09.And then
execute the following command in the piwik project.
php console core:archive --force-all-websites --force-all-periods=3715200 --force-date-range=2016-09-01,2016-09-30 --php-cli-options="-d memory_limit=6G"

I find that when I do not enter the --force-all-periods parameter, the command will be skipped.Only if I fill in the parameter --force-all-periods can I start to re-process the statistics in September.

The following command makes me wonder about the definition of the parameter --force-all-periods
php console help core:archive

Now even if it has been re-process statistics in September, but I am to the accuracy of the data to doubt.I fear that the October data will also statistics in September.