The user cannot be less than 0 years old, and more than 100 years old
//format birthday date req.validated.birthdate = moment(req.validated.birthdate, "DD/MM/YYYY").format("YYYY-MM-DD");
You can use moment().diff
const ageInYears = moment().diff(moment('15/11/1993', "DD/MM/YYYY"), 'years');
if (ageInYears > 100) {
alert('More than 100 years old')
} else if (ageInYears < 0) {
alert('Less than 0 years old')
} else {
alert('Age is fine')
}
Edit: Better code