Hi,
I've attached a small spreadsheet to demonstrate how you can do this. I was really bored at work this morning and it was kind of fun coding it. I put the creation of the new records on the on-click event of a button, but you can move that to anywhere you want. The date format is in MM/DD/YYYY so you'll have to change that for it to work right for your needs.
Good luck, let me know if this helps.
Stu