Optimal mode to hide the time of day description


What is the best method to cache the following? I am creating an intranet web application template that will display the message, e.g., Good Morning, Justin Satyr! near the top of my master page header. Obviously, I will have to determine whether to show Morning, Afternoon or Evening. For clarity, my code is below:

string partOfDay;
var hours = DateTime.Now.Hour;
if (hours > 16)
    partOfDay = "evening";
else if (hours > 11)
    partOfDay = "afternoon";
    partOfDay = "morning";

I do not want to re-determine this on each page load because that seems moderately redundant and because I have to poll a SQL server to retrieve the user's full name. What is the best way to cache this information? If I cache it for the length of the session, then if the user begins using the application at 11:00 AM and finishes at 3:00 PM, it will still say Good Morning.

Is the best thing to do simply re-determine the M/A/E word each page load and cache the person's full name for the session? Or is there a better way?

I would just keep the user name in the Session object, the rest honestly is not worth caching and checking if it is out of date etc., just re-run it on each page - provided you put the implementation into a common library /class so you keep your code DRY.