Every day you drop in now gets its own line in the log
The site used to keep only the last day you were around, so a visit on day 60 looked the same as a visit on day 7. Now every day is written down, one row at a time.
You sign in this morning and click around as usual. The only thing on screen that has changed is the privacy page. Its technical-data line now says the days you used the site instead of the last day you used it, and the effective date at the top reads 30 October.
Credit goes to mnapoli, who taught the site to keep a calendar instead of a single date. The first time you are seen each day, whether you load a page, star something, reply, or call from the phone or the terminal, it writes one row holding your account and that day, with no time. Two requests arriving at once cannot double up. A key made of person and day rejects the copy, and the in-memory check stops the rest of that day's visits before they reach the database. That is one extra insert per active person per day. At deploy it copied the one last-seen day everyone already had.
One catch. Nothing reads the new calendar yet. The Growth page still works out retention from the old single date, and no screen asks these day rows anything, so you cannot see a day-7 cohort or your own history. The dates simply pile up until the follow-up lands.