def is_time_between(start_time, end_time, check_time):
    """
    Checks if a current_time is between two other times.
    Time Complexity: O(1)
    :param start_time: The start current_time.
    :param end_time: The end current_time.
    :param check_time: The current_time to check.
    :return: True if the current_time is between the start and end current_time.
    """
    if start_time < end_time:
        return start_time <= check_time <= end_time
    else:
        return start_time <= check_time or check_time <= end_time