difInDays method
Implementation
int difInDays(DateTime? other) {
if (other == null) {
return 0;
}
if (isSameDate(other)) {
return 0;
}
final newThis = DateTime(year, month, day, 0);
final newOther = DateTime(other.year, other.month, other.day, 0);
return newOther.difference(newThis).inDays;
}