differenceInMonth method

int differenceInMonth(
  1. DateTime datetime
)

Implementation

int differenceInMonth(DateTime datetime) {
  int diff = 0;
  DateTime source = this;
  bool isBefore = source.isBefore(datetime);
  int delta = isBefore ? 1 : -1;

  while (!source.isSameYearMonth(datetime)) {
    source = source.addMonth(delta);
    diff += delta;
  }

  return diff;
}