import datetime

class Hour:
    _hour = datetime.datetime.now().hour

    def __init__(self):
        if int(self._hour) > 15:
            self.time_of_day = "День"
    #тут еще куча проверок

    def get_hour(self):
        return self._hour

class Minute:
    _minute = datetime.datetime.now().minute

    def get_minute(self):
        return self._minute

class Day:
    hour = Hour().get_hour()
    minute = Minute().get_minute()
    time_of_day = Hour().time_of_day

    def __str__(self):
        return "{}:{} \nВремя суток: {}".format(self.hour,self.minute,self.time_of_day)

d1 = Day()

print(Day())