please how to find a historical data according to rolling ric?
If i use CFI2Z1, i will get contract for DEC21, if i use CFI2Z2, i will get contract for DEC22 etc. But how to do it if i want to go back, and i need contract for DEC19 and DEC20?
There is the code for DEC21
Which ric use for DEC20 in this case?