how to subtract two dates in dart
int daysBetween(DateTime from, DateTime to) {
from = DateTime(from.year, from.month, from.day);
to = DateTime(to.year, to.month, to.day);
return (to.difference(from).inHours / 24).round();
//Using inHours instead of days b/c of daylight savings
}
//the birthday's date
final birthday = DateTime(1967, 10, 12);
final date2 = DateTime.now();
final difference = daysBetween(birthday, date2);