What happens if I'm late on a car insurance payment

If I was late by just I half A-day on my car or insurance payment, had accident later that night. I'm still insured under a clause correct?

It depends on the policy status. If you were just late with a bill but no cancellation was issued, then you are still insured. This is most often what happens if it's the first payment you missed. If a company issued you a cancellation notice for non payment and you miss that then the policy was cancelled at 12:01AM the day the notice says and no coverage is offered. I'd contact your agent and make sure your were insured at the time. But, if it's the first payment you've missed, you're probably okay.