In order to take the right actions on expiring certificates, it would be great to add extra fields to the certificate type entity.
- Validity: an amount of time (years, days) that you specify per certificate type, so that the system can automatically calculate the certificate expiration date based on the certificate start date + this new validity field
- Warning: an amount of time that (years, days) needs to be substracted from the certificate expiration date, to get the date when people should get warnings about certificate expiration