def create_time_schedule_url(quarter: str, year: str, sln: str) -> str:
    """
    :param quarter:
    :param year:
    :param sln:
    :return: URL for UW Time Schedule.
            Example: "https://sdb.admin.uw.edu/timeschd/uwnetid/sln.asp?QTRYR=AUT+2020&SLN=13418"
    """
    base_url = "https://sdb.admin.uw.edu/timeschd/uwnetid/sln.asp?"
    return f"{base_url}QTRYR={quarter}+{year}&SLN={sln}"