class Rufus::Scheduler::RepeatJob

def last_at=(last)
  @last_at = last ? Rufus::Scheduler.parse_to_time(last) : nil
  fail ArgumentError.new(
    "cannot set last[_at|_in] in the past: " +
    "#{last.inspect} -> #{@last_at.inspect}"
  ) if last && @last_at < Time.now
  @last_at
end