I get a panicked note from a customer begging to know when their domain expires.
Here's a pop quiz for you folks. How can you find out when your domain expires?
At the command line, do a whois and then the domain name.
Or look up the domain name with one of the many hundreds of whois tools at registrars and such.
If you registered anonymously or with a registrar that doesn't give out the expiration date, well, go to the registrar, sign in, and check your account.
Don't remember how to sign in to your registrar? That's between you and their customer service department.
Don't remember who your registrar is? Well, do a whois of your domain and you'll get the details on who the registrar is and how to contact that registrar.
Hell, a Google search for "when does my domain expire" gives you a link to a site that tells you to do a whois.
If every single one of those steps is completely alien to you, someone else should be running your website for you.