TLS / HTTPS · Let's Encrypt · 398-Day Rule · OpenSSL CLI · PEM Parser

SSL / TLS Expiry & Certificate Validity Planner

Track SSL certificate lifespan, schedule timely renewals before browser outages occur, decode raw PEM certificates, and audit compliance against the 398-day CA maximum lifetime rule.

Current Date:2026-11-02

Certificate Issue Date (Not Before):

Certificate Expiration Date (Not After):

Standard CA Validity Presets:

Remaining Validity59 Days

+13 hours remaining

Recommended Renewal Target2026-12-02

Renew 30 days before expiration to prevent outages

Total Validity Lifetime90 Days

&check; Compliant with CA/B Forum Ballot SC31

Certificate Lifetime Elapsed: 33.8%Valid until: 2027-01-01

Terminal Inspection Commands (OpenSSL)

Check live server certificate dates:

openssl s_client -connect speed-drain.com:443 -servername speed-drain.com 2>/dev/null | openssl x509 -noout -dates -subject -issuer

Check local file certificate (cert.pem):

openssl x509 -in cert.pem -noout -dates -subject

TLS Certificate Lifecycle & Industry Validity Standards

01.The 398-Day Maximum Validity Rule (Ballot SC31)

Historically, Certificate Authorities sold 3-year and 2-year SSL certificates. However, long-lived certificates prolonged the vulnerability window for compromised private keys and obsolete cryptographic algorithms.

Effective September 1, 2020, Apple Safari, Google Chrome, and Mozilla Firefox unilaterally capped maximum acceptable validity to 398 days (approximately 13 months). Any commercial certificate issued after this date with a validity exceeding 398 days is rejected with a fatal ERR_CERT_VALIDITY_TOO_LONG error.

Google has recently proposed reducing this limit further to 90 days for all publicly trusted certificates to encourage total automation via the ACME protocol.

02.Why Let's Encrypt Issues 90-Day Certificates

Let's Encrypt intentionally chose a 90-day certificate lifetime for two key architectural reasons:

Damage Limitation: If a server private key is leaked or stolen, an unauthorized actor can only abuse it for a maximum of 90 days.
Enforced Automation: Human sysadmins cannot manually update certificates every 90 days without missing a deadline. By adopting 90-day lifespans, organizations are compelled to automate renewal pipelines via Certbot, Traefik, or Caddy.

Let's Encrypt officially recommends initiating automatic renewal attempts when 30 days remain (at 66% through the certificate lifecycle).

03.The Catastrophic Cost of Expired Certificates

When a TLS certificate expires by even 1 second:

Browsers immediately display prominent full-screen red warning interstitials ("Your connection is not private").
Mobile apps and REST APIs crash instantly with SSL handshake termination.
Webhooks from payment gateways (Stripe, PayPal) fail immediately.
Search engine crawlers drop ranking because HTTPS endpoints appear offline.

04.Verifying SSL Validity from the Command Line

You can test the exact dates and issuer of any live website in 1 second via standard OpenSSL without opening a browser:

openssl s_client -connect example.com:443 -servername example.com \</dev/null 2>/dev/null | openssl x509 -noout -dates

Output will display notBefore=... and notAfter=... in GMT format.