contains method
- DateTime date
Returns true if this contains the given date. If the date is equal
to the start or end or is between the two dates, it will return
true.
Implementation
bool contains(DateTime date) {
return (startsBefore(date) || date.isAtSameMomentAs(start)) &&
(endsAfter(date) || date.isAtSameMomentAs(end));
}