Hi Dan,
Registrars often post this type of information on their web sites.
Your certificate shows an expiration date. In my experience Registrars prefer to do the recertification audit 3 months before the certificate expires, so as to leave time for corrective action (if any, including time to respond, actions and time for the auditor to review and close) and an office review to make sure everything is in order to re-issue the certificate.
I hope this helps.