Just a few days ago, I failed to practice until about 11:59. I only got one question done before the clock struck midnight, naturally, so the rest was counted towards the “next day’s” goal. However, despite not meeting my goal, neither streaks were reset.
Based on the discussion in this question about streaks, it would seem it might have to do with an issue of timezones. However, it’s very curious that it definitely knows I didn’t practice on the 26th but still left my streak.
I think this happened while practicing on Android Mobile, but since the bug seems to have carried over into the web version I’m posting it in the general bug-catching forum.
I’m pleasantly surprised that my lapse didn’t result in losing my streak, but I suppose it wouldn’t be fair to count that as a feature rather than a bug.