What is the longest you've had a cow go over due?

Just out of curiosity, what is the longest you've had a cow go over her due date?

I had two that calved right in between AI date and bull turn out. In the end I'll probably have to DNA the calves.

The longest I know for sure is 13 days over.

We had a very sad case this past spring. I had a cow go over 22 days. It was not good. I thought she was bull covered and she stuck AI. I do not mess around any longer. Because our operations so small 1 or 2 deaths cuts pretty deep. I have them vet checked. I am very lucky I have great resources close by.

14 days. identified to the AI sire due to color. surprisingly only about 90lbs

11-12 days

21 days, then it was up side down and backwards. Not sure what characters to use for the words that I used, but like a post above figured she had not caught the AI and was bull covered.

Right now I have a heifer that was due September 29. She is ai'd to lowline bull doc holliday. No clean up bull. I am getting a vet to check her because I am getting worried. But she hasn't had mucous and still needs more milk in my opinion before she goes