Fix NET::ERR_CERT_DATE_INVALID

TL;DR

Your browser says a website’s security certificate is invalid because the date on it isn’t right (usually in the future). This guide shows you how to temporarily work around this, and then how to fix the real problem.

Understanding the Error

NET::ERR_CERT_DATE_INVALID means your computer thinks the website’s security certificate is either from the future or too old. This usually happens if the website’s server clock is wrong, or if there’s a problem with how the certificate was created.

Temporary Workarounds (Use With Caution!)

Warning: These methods bypass security checks and should only be used for testing or on websites you trust. They make your connection less secure.

1. Chrome/Edge – Command Line Flag

1. Close all Chrome/Edge windows.
2. Open a command prompt (Windows) or Terminal (Mac/Linux).
3. Run Chrome/Edge with the following flag:

   chrome --ignore-certificate-errors

   (On Mac, you might need to specify the full path to your Chrome application.)

4. This will launch Chrome/Edge ignoring certificate errors. Visit the website again.

2. Firefox – about:config

1. Type about:config in the address bar and press Enter.
2. Accept the risk warning (be careful!).
3. Search for security.tls.insecurefallbackhosts.
4. Double-click it to set its value to true.
5. Restart Firefox.

Fixing the Root Cause

The temporary workarounds don’t solve the problem; they just hide it. Here’s how to fix things properly:

1. Check Your System Clock

1. Windows: Right-click on the clock in the taskbar, select ‘Adjust date/time’. Make sure ‘Set time automatically’ is turned on.
2. Mac: Go to System Preferences > Date & Time. Make sure ‘Set date and time automatically’ is checked.
3. Restart your browser after checking the clock.

2. Clear Your Browser Cache

Old cached data can sometimes cause certificate issues.

1. Chrome/Edge: Press Ctrl+Shift+Delete (Windows) or Cmd+Shift+Delete (Mac). Select ‘Cached images and files’ and click ‘Clear data’.
2. Firefox: Press Ctrl+Shift+Delete. Select ‘Cache’ and click ‘Clear Now’.

3. Website Server Issue

If the problem persists, the website’s server might be misconfigured.

• Contact the website administrator or support team to report the issue. They need to fix their certificate setup.

4. Antivirus/Firewall Interference

1. Temporarily disable your antivirus software and firewall.
2. Try accessing the website again. If it works, your security software is likely interfering.
3. Add an exception for the website in your antivirus/firewall settings. Consult your software’s documentation for instructions.

5. Check Certificate Details (Advanced)

You can examine the certificate directly to see if there are any obvious problems.

1. Click the padlock icon in the address bar.
2. Select ‘Certificate’ or ‘Connection is secure’.
3. Look at the ‘Valid from’ and ‘Valid to’ dates. If they’re incorrect, it confirms a server-side issue.