Activation, one signup day at a time
The Metrics tab now charts activation for each day people signed up, not just the whole range. Days still filling their first twelve hours show lighter, and a hover tells you how many sign-ups the bar measures.
Open Operations → Metrics and the funnel now stands above two charts. Daily active users comes first. Then comes the new one. It gives a slot for every day in the range, with a bar on the signup days that are old enough to judge. Hit 7d, 30d, or 90d, or all time, and the bars run back to the first signup. Hover a bar and you get the date, 'so far' if the day is still filling, and a line like '33.3% of 3 sign-ups.'
Credit goes to mnapoli, who split the activation count into one bucket per signup day. The query takes signups at least twelve hours old, groups them by UTC calendar day, and applies the same test as the funnel. That test is starring or saving commits by three different people, or a reply, a quote, or a star from someone else on your own post. Nothing new is stored. It reads users, stars, bookmarks, and posts already there, so all time reaches back to launch. Each bar is activated ÷ sign-ups old enough to judge, printed to one decimal, and a day turns light to solid at noon UTC the next day, once its last signups have had their twelve hours.
One catch. A day where nobody activated draws a bar zero pixels tall, so it looks exactly like a day with no signups, until you hover and the tooltip says '0.0% of 4 sign-ups.' The slot is there. The ink is not.