Section 32 states to use "the yield on Treasury securities having comparable periods of maturity to the loan maturity as of the 15th day of the month immediately preceding the month in which the application for the extension of credit is received by the creditor,..."
The example given on the Federal Reserve Bank of Dallas web site
http://www.dallasfed.org/htm/pubs/e-perspec/2002/2_2n.html specifically shows that you go to the H15 Federal Reserve Statistical Release, Treasury Constant Maturities with a comparable maturity to the loan, and look under the WEEKLY (FRI)tab.
This seems to be the weekly average. I have seen posted on a thread that you use the daily rate, not the weekly average. Does anyone know which is correct? Could it be that the Fed made a mistake in its example? Thank you.