Time Series 
A time series is a set of data that is distributed over time. For input, you can provide Demand Data Foundation (DDF) with different time series containing historical demand data. Based on this data, the historical demand can be modeled (demand modeling), and based on the demand modeling results, the future demand can be forecasted (demand forecasting). Note that you need the Unified Demand Forecast (UDF) component to model and forecast demand.
For output, DDF generates two time series containing the results of demand modeling and demand forecasting, respectively.
Recommendation
You should provide 2 years of historical demand data to ensure the proper interpretation of seasonality, trend, and other yearly demand influencing factors (DIFs).
Make sure that your historical data is at daily granularity. Weekly data is currently not supported. For more information, see Customizing (transaction SPRO) under
Cross-Application Components 
Demand Data Foundation Imported Data Time Series Define Time Series for Key Figure Configuration 
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Integration
DDF can receive different types of time series from external SAP or non-SAP applications. For more information, see Integration Information.
Features
DDF supports the following time series:
Generic (historical consumption data)
Sales (historical POS data)
SAP HANA Content for DDF with UDF (virtual data models providing historical POS data or sales orders and also supporting the integration of historical promotions available in SAP ERP)
Model (results of demand modeling)
Forecast (results of demand forecasting)