My yubicrypt certificate is valid from Jan 01 2026 - Jan 01 2027.
https://github.com/Ch1ffr3punk/yubicrypt
You can examine it with 'openssl x509 -in mycert.pem -noout -text'.

-----BEGIN CERTIFICATE-----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-----END CERTIFICATE-----