ElephantSQL servers created prior to September 2020 have a SSL certificate that will expire on October 18, 2020. We will replace those certificates on Friday the 16th October 0800 UTC.
We expect that few customers will notice this change. Most modern trust stores have the root certificate that signed the elephantsql.com certificate already stored.
If your client is unable to verify the signed certificate, the root certificate can be downloaded from here: https://crt.sh/?id=1199354
Once this root has been downloaded, install it into your client machine's certificate trust store.