Interest calculation U/s 50 og Cgst Act

Phanendra (student) (22 Points)

09 March 2020  
Sir/Madam , from what date interest under section 50(1) of Cgst act @ 18% will be calculated?

Whether from the original due date of 3B for that month

or

Whether from extended due date, as in few cases CBIC has extended the due date.
Eg: During 2017-18, Cbic has extended the due date to 23rd or 25th of the next month to file 3B.

Kindly assist.
Thanks in advance.