There can be different versions of X509 used by organizations, when creating digital certificates. You can determine the exact version number by looking at the standard line items contained in the digital certificate. You will see a line, which says version number, which will be the numbers after the period behind the 9. An organization may decide to modify their digital certificates on a regular basis, and with each modification, may result in a new version number being created.
You Can Include an Expiration Date in Your X509 Certificates
Besides showing you the version numbers, an X509 certificate format will also provide other types of useful information. You can find the creation date of the certificate and the expiration date of the certificate. The expiration date may not be used by some organizations, so this entry may be blank. However, by using an expiration date, your certificates automatically expire and eliminate having to worry about remembering who has one of your digital certificates.