Your Web browser software relies on correct date and time settings to make secure connections to the Internet.
If the date and time are not correct, an alert box may appear with a message such as "unable to establish a secure connection" or "can't verify identity." The exact words vary with different Web browsers, but it might look like this message from Safari:
There could also be other causes. To avoid this issue, follow these steps:
- Be sure that your Date & Time control panel settings are correct.
- Try a different Web browser.
- Download the latest versions of your Web browsers.
- If you still cannot make a secure connection, notify the contact listed on the affected Web site.
- In Mac OS X 10.3, 10.4 or later, you can use Keychain First Aid to resolve potential keychain issues.
Why Date and Time?
A common cause for this issue is incorrect Date & Time settings. Some Web sites use encryption to protect your data while in transit, particularly when making purchases, financial transactions, or conveying other sensitive information. To be sure that only "trusted" Web sites can make a secure connection to your computer, the Web browser queries the site for a valid security certificate. Because certificates are issued and expired like a driver's license, your Web browser perceives that a proper certificate is invalid if your computer is set to a date outside the range of the certificate.