lastDayInPreviousMonth method

DateTime lastDayInPreviousMonth([
  1. int firstDay = 1
])

上月最后一天

firstDay - 每月起算日期，assert(firstDay > 0 && firstDay < 29)

Implementation

DateTime lastDayInPreviousMonth([int firstDay = 1]) {
  return firstDayInMonth(firstDay).subtract(Duration(days: 1));
}