IIS 7.0 has a nice feature of creating self-signed certificates … very handy for creating test certificates.
I was recently asked if there is a way to modify the validity period of the certificate it creates.
The module that creates the certificate uses a simple logic of incrementing the year by 1. Something like
SYSTEMTIME systemtime = new SYSTEMTIME();
systemtime.wYear = (short) (DateTime.Now.Date.Year + 1);
systemtime.wMonth = (short) DateTime.Now.Date.Month;
systemtime.wDay = (short) DateTime.Now.Date.Day;
It’s hardcoded and hence the validity of the certificate will always be 1 year from the current date.
Also the name of the certificate will always be the FQDN.
In case you want to create certificates with a shorter validity period or different names there are are a lot of tools like SelfSSL that you can use to generates self-signed certificates.