NET::ERR_CERT_DATE_INVALID
Chrome shows this when the certificate is outside its validity window — either expired, or its notBefore date is in the future.
Common causes
- The certificate has expired (the most common case).
- The certificate isn’t valid yet — its start date is in the future.
- The device’s clock is set incorrectly.
How to fix it
- 1
Check the certificate’s validity window:
echo | openssl s_client -servername example.com -connect example.com:443 2>/dev/null \ | openssl x509 -noout -dates - 2
If it’s expired, renew and redeploy the certificate, then reload the server.
- 3
If only one device is affected, correct that device’s system clock.
Catch these before your users do
SSLNudge detects NET::ERR_CERT_DATE_INVALID and expiry issues daily and alerts you.