datetimeRange property
Implementation
@override
DateTimeRange get datetimeRange {
final DateTime end = now;
final int endMonth = end.month;
int startMonth = endMonth - value;
DateTime start;
if (startMonth > 0) {
start = DateTime(end.year, startMonth, end.day + 1);
} else {
startMonth = 12 + startMonth;
start = DateTime(end.year - 1, startMonth, end.day + 1);
}
return DateTimeRange(start: start, end: end);
}