For the users that doesn't mind sharing their birthday date, could have a input on the settings to insert their birthday date (and also remove easily if they want)
On their birthday date, could also add a birthday badge (maybe a party-hat? 🎉) to indicate it's their birthday.
For the users that doesn't mind sharing their birthday date, could have a input on the settings to insert their birthday date (and also remove easily if they want)
On their birthday date, could also add a birthday badge (maybe a party-hat? 🎉) to indicate it's their birthday.