with Flow("Load Daily Tables", schedule) as flow:
    start_date = Parameter('start_date', default='')
    end_date = Parameter('end_date', default='')

    dates = daterange(start_date, end_date)
    # dates = ['2020-09-29', '2020-09-30']

@task(log_stdout=True)
def daterange(start_date, end_date):
    print(start_date, end_date)
    list_of_dates = []

    # Keep the parameters short you can leave end_date blank and it will default to today. 
    if end_date == '':
        eastern = timezone('US/Eastern')
        single_date = datetime.now(eastern)
        end_date = single_date
    # If start_date is blank we are just going to pull yesterday
    if start_date == '':
        eastern = timezone('US/Eastern')
        start_date = datetime.now(eastern)
    elif start_date != '':
        start_date = datetime.strptime(start_date, '%Y-%m-%d')
        # Make start_date eastern
        start_date = start_date.replace(tzinfo=eastern)
 # Otherwise we are going to get a list of dates.
    for n in range(int((end_date - start_date).days)):
        single_date = (end_date - timedelta(n)).strftime("%Y-%m-%d")
        list_of_dates.append(single_date)

    print(list_of_dates)
    return list_of_dates

schedule

list

(prefect) dylanhughes@Dylans-MacBook-Pro-Prefect ~/Desktop> ipython -i test.py
Python 3.7.7 (default, Mar 26 2020, 10:32:53)
Type 'copyright', 'credits' or 'license' for more information
IPython 7.13.0 -- An enhanced Interactive Python. Type '?' for help.
---------------------------------------------------------------------------
NameError                                 Traceback (most recent call last)
~/Desktop/test.py in <module>
     35     # Two lists. dates and tables
     36     # [date1, table1], [date1, table2], [date2, table1], [date2, table2]
---> 37     combos = list(product(table_list, dates))

NameError: name 'product' is not defined