Blink and you'll miss them: 6-day certificates are here!

Let's Encrypt now offers 6-day validity certificates through their 'shortlived' profile, accessible via ACME clients like acme.sh. Google Trust Services also provides short-lived certificates with configurable validity periods, even down to one day. The shift toward shorter certificate lifespans (with industry moving to 47-day maximum by 2029) emphasizes the importance of automation, as ACME-based certificate renewal makes validity period largely irrelevant once properly configured.