10.9. The Certificate is Out of Date.

If some systems are reporting out of date certificates, the system cannot download files or use SSH to connect.

10.9.1. Typical Output

curl -fgLO https://opscode-omnibus-packages.s3.amazonaws.com/el/6/i686/chef-11.18.12-1.el6.i686.rpm
curl: (60) Peer's Certificate has expired.
More details here: http://curl.haxx.se/docs/sslcerts.html

10.9.2. Likely Cause

If the system clock is out of date (or has bad batteries), it resets to a date that does not match certificate validation ranges.

Update the system clock. The batteries may need to be replaced in the system to solve the issue.