Update formula automatically upon insertion of new row

[spongeavenger]

I want to write a formula including =DATEDIF() but this question probably applies to other functions as well. The dates are contained in a column. Of course DATEDIF() requires a start_date and end_date. If the start_date is A2 and the end_date is A100 then my formula is =DATEDIF(A2, A100, "M").

My question is: when new dates/rows are added (e.g. A101, A102, etc.), how can I update the =DATEDIF formula automatically?

 

[gargamalebarbosa]

Try please

DATEDIF(A1,LOOKUP(2,1/(A:A<>""),A:A),"M")