当sql server脱机时，禁用（礼貌地）网站

I work at a college and have been developing an ASP.NET site with many, many reports about students, attendance stats... The basis for the data is a ms sql server db which is the back end to our student management system. This has a regular maintenance period on thursday mornings for an unknow length of time (dependent on what has to be done). I work at a college and have been developing an