I have a date of operation. I want create promissory notes which have got:

day=1
month= the next month of operation_date
year= automatic

Example :

operation_date = 15/11/2010 
promissory_note1_date = 1/12/2010
promissory_note2_date = 1/01/2011
promissory_note3_date = 1/02/2011
promissory_note4_date = 1/02/2011

if exist four promissory notes

How could I make it?

PD: Excuse me my syntax

ruby-on-rails ruby
Edit
Report