Why does IIS / ASP.Net / MVC3 set the maximum age to 7200?

Question

I have an ASP.Net MVC 3 web application that I use to deliver files (in this particular test, in pdf files). Files will not change (if the file changes, a new URL will be created). Therefore, I would like to set the maximum age (for Cache-Control) to 31536000 (1 year).

the code...

Response.Cache.SetMaxAge(TimeSpan.FromDays(365));

Fiddler's answer ...

Cache-Control: private, max-age=7200

However, if I set the maximum age to less than 7200, it works just fine ...

the code...

Response.Cache.SetMaxAge(TimeSpan.FromSeconds(7199));

Fiddler's answer ...

Cache-Control: private, max-age=7199

I tried to set the [OutputCache] attribute for this action with the same results.

Any idea that 7200 follows, and how to let it be bigger?

Answer 1

, max-age - . SetMaxAge MSDN:

SetMaxAge , .

max-age 7200, , , . .