RD API Intraday Historical Prices

I am using historical_pricing.summaries.Definition RD API function and am trying to get intra-day prices at one minute intervals for a specific date. What should I set for the start and end dates ?

response = historical_pricing.summaries.Definition(

rics_list,

start=start_date_ts,

end=end_date_ts,

fields = fields_list,

interval= historical_pricing.Intervals.ONE_MINUTE).get_data()

resp = response.data.df