We have switched to issuing 64 day certificates in our staging environment for the classic certificate profile.
On February 10, 2027, all Let’s Encrypt subscribers will move to certificates with 64 day lifetimes by default unless they select an even shorter lifetime (45 or 6 days, as previously announced). This means that any certificate we issue or renew on and after that date will have a 64 day validity period, and we expect the last 90-day certificate to expire on May 11, 2027. We will not revoke valid certificates as a part of this process.
For more information, see the blog post we recently posted.