generate config dictionary to pass to add() or remove()

        Args:
            month (int): month in a year, from 1 to 12
            week (int): week in a month, from 1 to 4
            day (int): day in a month, from 1 to 31
            weekday (int): weekday in a week, from 0 to 7. 0 and 7 both represent Sunday
            hour (int): hour in a day, from 0 to 24
            minute (int): minute in an hour, from 0 to 59

        Returns:
            dict: a dictionary with form {'Day': 1, etc}

def gen(self, month=0, week=0, day=0, weekday=0, hour=0, minute=0):
        '''generate config dictionary to pass to add() or remove()

        Args:
            month (int): month in a year, from 1 to 12
            week (int): week in a month, from 1 to 4
            day (int): day in a month, from 1 to 31
            weekday (int): weekday in a week, from 0 to 7. 0 and 7 both represent Sunday
            hour (int): hour in a day, from 0 to 24
            minute (int): minute in an hour, from 0 to 59

        Returns:
            dict: a dictionary with form {'Day': 1, etc}
        '''
        dic = {
            'Month': month,
            'Day': day,
            'Week': week,
            'Weekday': weekday,
            'Day': day,
            'Hour': hour,
            'Minute': minute
        }
        dic = {k: v for k, v in dic.items() if v != 0}
        return dic