Chrome, Edge

NET::ERR_CERT_DATE_INVALID

The certificate is outside its validity window — nearly always expired, occasionally not yet valid.

What causes it

Automated renewal stopped working weeks ago and nobody noticed.
A manual certificate nobody diarised.
The visitor's device clock is wrong.

If you are the visitor

Check your device date and time first — a wrong clock breaks every HTTPS site at once.

If it is your website

Renew immediately, then find out why the automation failed.
Check expiry monthly, or monitor it, rather than trusting the renewal to be silent and reliable.

Find out whether the site is down for everyone

A live check from our server shares nothing with your network — it settles the question in seconds.

Run a live check

Other connection errors

ERR_CONNECTION_REFUSED DNS_PROBE_FINISHED_NXDOMAIN ERR_NAME_NOT_RESOLVED ERR_CONNECTION_TIMED_OUT ERR_SSL_PROTOCOL_ERROR NET::ERR_CERT_AUTHORITY_INVALID NET::ERR_CERT_COMMON_NAME_INVALID ERR_TOO_MANY_REDIRECTS ERR_EMPTY_RESPONSE ERR_CONNECTION_RESET 503 Service Unavailable 502 Bad Gateway This site can't be reached