Static variables glued to a request (and not to the application)

 Hello,
 Currently, in my web application, I've static variables enabling me do put parameters, etc. in an easy to access class, from anywhere in the application.
The point is that I would like to put in it some *page* parameters (ie I would like the content of it not to be saved into the application state but to be "page request depend").
For example, consider the my public static datetime Parameters.StartCalculation ; I automatically set the query start datetime when loading. There is no sense to have this variable "cross users", I want this variable "glued" to the page (ie replicated in each "user request thread" which can do everything on it without changing the state of other requests).
 How can I do this?
 
Thanks for your help, this is driving me crazy!!!

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