我正在尝试在打开它时自动更新Excel工作表中的日期和时间

I have a website that needs to update date and time and reference number as I open the excel sheet template. How can I do that? Let's just say a customer is calling to make a reservation and as I open the excel sheet my current date and time and reference fields must be updated automatically. How can I do this. Any help will be appreciated.I have a website that needs to update date and