Itc claim missed in gstr3b of a month,how to claim in future

I have missed to claim ITC against some purchase invoices in my Nov/Dec2018 GSTR3B, so how to claim those in subsequent months?

They are now showing in GSTR2 as filed by the supplier. But these ITC amount is not showing in credit ledger. Without showing in the credit ledger I may not be able to adjust them against my tax liabilities.

Do I need to add these ITC amounts in the ITC column of the subsequent month's GSTR3B i.e. JAN/FEB18 GSTR3B? but..
If I show/add  these ITC in the JAN18 or FEB18 GSTR3B then technically there will be a mismatch in the Date of ITC(i.e. Date of purchase) and the date of claim is this ok? i.e. the Date of actual ITC(i.e. purchase) is NOV/Dec18 but I am showing these in the JAN/FEB GSTR3B