Creating aging Bucket column based on date

Hello,

Currently days are calculated based on "Todays date()-Service Date" and by the running conditional formula Im deffining aging category in Bucket column i.e 0-30 "if days <= 30 thn 0-30 else if days <=60 thn 31-60". Is there any way I can create 0-30, 31-60,61-90,...365+ coulmn, where it will pull outstanding balance and locate it under right aging bucket. My goal is to calculate month over month change, which is not possible with the current technique im using for the anlyses puposes

Thank you for the help