import datetime

class car():

    def __init__(self, color,make,model,year,maintanenance_freq):
        self.color=color
        self.make=make
        self.model=model
        self.year=year
        self.maintanenance_freq=maintanenance_freq

    def vehicle_age(self):
        now = datetime.datetime.now()
        return(now.year-self.year)

    @classmethod
    def maintenance_window_cls(cls,window):
        cls.maintanenance_freq = window
        return cls.maintanenance_freq

car1= car("Green","Honda","Accord",2014,12)
car2= car("White","Lexus","NX",2017,12)


car.maintenance_window_cls(6)

print(car2.maintanenance_freq)