Syntax: TBILLEQ(S, M, D)
S = Settlement date
M = Maturity date
D = Discount rate of Treasury bill
TBILLEQ returns the bond-yield equivalent (BEY) for a Treasury Bill equivalent to a bond, given settlement date S, maturity date M, and discount rate D. Dates must be expressed as serial date values. If the term is one half-year or less, BEY is equivalent to a actural/365 simple interest rate. If the term of the security is more than one-half year, BEY is equivalent to a semiannually compounded Treasury bond yield.
TBILLEQ(DATE(93, 3, 31), DATE(93, 6, 20), 9.14%) = 0.09462
TBILLEQ(DATE(93, 3, 31), DATE(93, 12, 15), 9.14%) = 0.09819
Excel function: N/A