```release-note:bug
command: `operator diagnose` certificate expiration warnings now contain the
correct time to expiration.
```

```release-note:improvement
command: `operator diagnose` certificate expiration warnings are now raised
if less than 15% of the certificate's validity period remains. Previously, any
certificate that was set to expire in the next 30 days would be flagged. This
made little sense for short-lived certificates.
```
