Thanks for detailed explanation, I can confirm this. My bill generation date is 3rd of every month while SBI reports to CIBIL on 26th.At first, I thought the same but the thing is SBI reports the Total Outstanding Balance as on the Statement (Bill Generated) to the CIBIL after 23 days of Bill Generation i.e. Due Date (which is 20 days from Bill Generation) + 3 days.
Let's say
Bill Generation Date: 1st of Every Month
Due Date: 21st of Every Month
CIBIL Reporting Date: 24th of Every Month (outstanding amount as of Generated Bill on 1st).
The customer care person also said that if anyone defaults or is not paid the Min Due Amount will be reported after 3 days from the Due Date.