Игорь Соколов

import datetime
import itertools


class MyTimer:
    def __init__(self, first_time_in_datetime, delta=10, target_time_in_datetime=None):

        self.current = self.repair_first_time_type(_first_time=first_time_in_datetime)
        self.target_time_in_datetime = self.repair_target_time_type(_target_time=target_time_in_datetime)
        self.delta_in_minutes = delta
        self.zero = self.target_time_in_datetime < self.current

    def repair_first_time_type(self, _first_time):
        return self._repair_time_type(_first_time)

    def repair_target_time_type(self, _target_time):
        if _target_time is not None:
            return self._repair_time_type(time_data=_target_time)
        else:
            return datetime.time(23, 59)

    @staticmethod
    def _repair_time_type(time_data):
        result = datetime.time(20)
        if isinstance(time_data, datetime.time):
            result = time_data
        if isinstance(time_data, str) and ':' in time_data:
            try:
                _hour, _minute, *_ = time_data.split(':')
                result = datetime.time(int(_hour), int(_minute))
            except TypeError:
                print('Need ISO format time. Time set to 20:00:00')
            except ValueError:
                print('only numbers and :. Time set to 20:00:00')
        return result

    def _add_time(self, tm=None):
        if tm is None:
            tm = self.current
        fulldate = datetime.datetime(100, 1, 1, tm.hour, tm.minute, tm.second)
        fulldate = fulldate + datetime.timedelta(minutes=self.delta_in_minutes)
        return fulldate.time()

    def add_time(self):
        self.current = self._add_time()
        self.zero = self.zero and self.current > self.target_time_in_datetime

    @property
    def next(self):
        return self._add_time()

    @property
    def check(self):
        if not self.zero:
            return self.current >= self.target_time_in_datetime
        else:
            return self.current < self.target_time_in_datetime

    def __repr__(self):
        return self.current.isoformat(timespec='minutes')


def write_file_from_data(data, filename):
    with open(filename, 'wt') as target_file:
        target_file.write('\n'.join(data))


def make_names():
    return [input(f'введите {i}:') for i in 'abcv']


def make_data(_counter):
    result_data = []
    while not _counter.check:
        time_from, time_to = _counter, _counter.next.isoformat(timespec='minutes')
        result_string = f'{time_from}-{time_to} @{next(names)}'
        result_data.append(result_string)
        _counter.add_time()
    return result_data


if __name__ == '__main__':
    names = make_names()
    # names = ['aaa', 'bbb', 'ccc', 'ddd']
    names = itertools.cycle(names)

    result_filename = 'result.txt'

    first_time = '20:00'
    target_time = '00:00'
    delta_in_minutes = 10
    counter = MyTimer(first_time, delta_in_minutes, target_time)

    write_file_from_data(data=make_data(counter), filename=result_filename)