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Usage of the back_to parameter

The back_to parameter is a datetime parameter in CloudQuant Data Liberator queries that defines the start point of a time range for data retrieval.

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Parameter format

You can specify back_to in two ways: Date only: 
'2024-07-08'
CloudQuant Data Liberator interprets this as midnight: '2024-07-08 00:00:00.000000' Specific time: You can set it to any time down to nanosecond precision.

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Important notes

All CloudQuant Data Liberator times are New York Time (US ET).
Start with small queries to understand data amounts before requesting large date ranges.
  • If back_to is omitted or set to None, CloudQuant Data Liberator returns the most recent value at the specified as_of time.

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Default behavior example

Without back_to, the query returns the latest available data: 
df = liberator.get_dataframe(liberator.query(
    name = 'daily_bars',
    as_of = '2023-12-25',
    symbols = ['GOOG', 'AAPL', 'MSFT']
))
Since December 25, 2023 was not a trading day, CloudQuant Data Liberator returned data from the most recent trading day (December 22, 2023).