function isOver18(dateOfBirth) {
// find the date 18 years ago
const date18YrsAgo = new Date();
date18YrsAgo.setFullYear(date18YrsAgo.getFullYear() - 18);
// check if the date of birth is before that date
return dateOfBirth <= date18YrsAgo;
}
isOver18(new Date("1999-12-01")); // true
isOver18(new Date("2020-03-27")); // false