SSL expiry monitors

Watches a certificate’s expiry date, evaluated from the TLS handshake during an HTTPS check (or as a standalone monitor against host + port 443).

Warning schedule

Fixed thresholds: 30, 14, 7, and 1 day before expiry. Each threshold fires its own alert email — never an incident, since an expiring-soon certificate isn’t downtime yet.

Most hosts auto-renew via Let’s Encrypt or another ACME client — these alerts are your early warning if that renewal silently failed.