Then you store the user age every time it's run and check for changes on start. Maybe that only gives you a 7 day range for birthdays, but you can narrow that over time and it's still good enough for targeting.
I agree, sorry, I think my original comment was a little imprecise. My point was that the app can get the “exact” age only for users who undergo an age-bucket transition in an era that the app has logs for.
I mean, the app can query on a weekly basis, and then if you go from “under 18” to “over 18” it knows the week that you were born in. But, if the user was already an adult when the logging started, there isn’t a transition to go off.
I mean, the app can query on a weekly basis, and then if you go from “under 18” to “over 18” it knows the week that you were born in. But, if the user was already an adult when the logging started, there isn’t a transition to go off.