Perhaps something like a "moving average" would be better to motivate people to keep things going without creating an expectations bubble. "You did great for t

Perhaps something like a "moving average" would be better to motivate people to keep things going without creating an expectations bubble. "You did great for the past 4 weeks - perfect streak" or "you are doing really well - only missed one day in the past 4 weeks". You know, something a human might say. Start off with a x Days, then switch to x Weeks and then moving average.