如何在上次修改日期的一天后刷新xml缓存？

I am developing a web app using ASP.NET 2.0 (C#), where on home page I am displaying recently added records. Adding of records frequency is around 1-5 records per day, so I decided not to put much overhead on the sql server by fetching recent records every time from db server. I am developing a web app using ASP.NET 2.0 (C#