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NET::ERR_CERT_DATE_INVALID: How to Fix It

The site's certificate is outside its valid dates, either because it really expired or because your device's clock is wrong.

NET::ERR_CERT_DATE_INVALID

Certificates are valid only between two dates. Either the site's certificate expired, or your device's clock is so far off that it looks expired or not yet valid.

Quick checks

  • Check your device's date, time and time zone.
  • If many sites show it, your clock is wrong; if only one does, the site's certificate expired.

Fixes on Mac

  1. Set the clock automatically

    1. System Settings › General › Date & Time: turn on Set time and date automatically and check the time zone.
    2. If the time keeps resetting on an older Mac, its clock battery may be failing.

  2. Check the certificate's dates

    1. Click the icon left of the address › Connection is not secure › certificate details, and read Valid From / Valid To.

Fixes on Windows

  1. Sync the clock

    1. Settings › Time & language › Date & time › Sync now.

Other devices

  1. Phones

    1. Turn on automatic date and time in settings.

Still not working?

If only one site shows it and your clock is right, the site's certificate expired. Tell the site; owners should renew it and automate renewals (for example with an ACME client like certbot).

ERR_CERT_REVOKED is different: the CA cancelled the certificate, often after a key compromise. Don't continue; the site must install a new certificate.

See what’s happening

LightAtom's connections view shows the server your browser is talking to, handy to confirm you reached the site you meant.

Frequently asked questions

Why does my computer say every certificate is invalid?

Your clock is wrong. Certificates are checked against your device's date, so a clock set to years ago or ahead breaks every HTTPS site. Turn on automatic time.

Can I ignore NET::ERR_CERT_DATE_INVALID?

Not safely on sites where you log in or pay. An expired certificate may be a harmless oversight, but the browser can't tell that from an attack.

How long are certificates valid?

Under CA/Browser Forum rules, public TLS certificates have been limited to 200 days since March 2026, dropping to 100 days in 2027 and 47 days in 2029. Short lifetimes are why renewals should be automatic.

Related errors and tools

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LightAtom team

The people who build LightAtom, a network monitor for macOS.