Warning: Some MS 365 formulas that might not work with prior versions of Excel.
Back in April I publish a post called Daily Treasury Security Rates. That post featured an Excel workbook that downloaded U.S. Treasury rates for the current month. This new workbook has Treasury rates starting 1/2/1990 and can be updated daily, when the markets are open and after the market closes. That is 30 years of daily rates.
There are very few things in this workbook, that you could not find on the web, however you may find some of sheets usefull.
I am not going to go into detail here, because I think the workbook is relatively easy to navigate.
Here are the contents: