Create Task 18 Months after Opp created date

Hi all, 

 I am looking for some support in create flows in SF. I have been tasked to create a task when certain products are past the 18 months mark from the opportunity created date. I am using a scheduled flow where the conditions are based on the product codes (from opportunity product object). 

This then goes to a decision element based on conditions Opp stage = Won. I then need to add a resource that detects if the opportunity created date is greater than 18 months but I am struggling on the formula for this. I don't believe today () + 547.501 would work as I have historical opportunities that are closed won prior from today.

This then based on the conditions raises a task to the opportunity owner.

Any guidance is much appreciated.