Hi Matthieu; the timezone and every other entry is absolutely correct! We have verified it numerous time. However this is what we found yesterday:
We found the archive_blob table under column ts_archived had a date which was a day ahead than the items tracked for. This was when we had piwik set to Auto archive.
We selected ‘No’ for auto-archiving, and ran a cron job to put data in Archive table. Then we found the correct dates are getting into the same column.
We don’t know the reason yet for this. Any suggestions?
It’s very interesting, and is something we must follow up! I would like you to create bug report with your information on: Issues · matomo-org/piwik · GitHub and we will surely investigate and solve this issue eventually thanks.