There is a way to do this natively, bit the details of the steps are too much to explain in detail with syntax on this forum.
Essentially you are looking to create "X number" of child records depending on the data entered in the Parent.
To to this I would make a table where the key field is user.
Then create a button which would either add the user to the table or edit the existing userid for the current user with the details of the current user's data entry on the Parent. I would then flow that to a table pre-loaded with say 100 records with Record ID# from 1 to 100.
I would then have each record calculate the value needed in the child table. For example the first record would calculate the three fields needed in your example
Yes,Feb,1(beacause full month),
Then the same button would then do a API_RunImport to copy the needed records (in this case 5 records, so Record ID 1,2,3,4 and=5 )
to the Child table and link them up with the focus Parent record.
Contact me off line via the information on my website
QuickBaseCoach.com if you require one on one assistance to get this working.