28 days late car payment?

I have my LAST car payment due ( 6 years of on time payments!!) and this car payment will have to be late. My money can only handle certain bills this month and my car payment is not one of them, My lender is WELLS FARGO BANK theyve been nice my whole term. I calculated that i will be able to pay my car payment 28 days late. will this show up on my credit score?? or does it have to be over 30 days late?????