Starting 1st September 2020, Safari announced to cut down the TLS Certificate validity to one year or 398 days including the renewal grace period. That means any certificate issued after 1 September with more than 398 days of validity will be rejected by Apple’s Safari browser.
It is a bold move aim to improve the web security, forcing devs to use Certificates with latest cryptographic standards. Effectively it reduces the time period in which a old neglected certificate can be exploited.
However it also mean the hassle of renewing certificate and handling/renewing private key securely. Renewing process can be automated but still lot of people do it manually for various reason.