TBILLYIELD Function (OpenOffice Calc)

• Introduced: First release not established; documented by OpenOffice.org 3.3.
• Supported in: Apache OpenOffice 4.1.16; this is a verified release, not a final supported version.
• Scope: Desktop Calc, English function names and semicolon-separated formulas.
• Checked: October 14, 2026. Eight ordinary reference formulas were recalculated from generated ODF in 4.1.16 on Linux x86-64, Build 9816. Source and independent arithmetic were checked.

TBILLYIELD returns an annualized investment-based yield using (100/Price-1)*360/d. In Apache OpenOffice 4.1.16, d is the US 30/360 difference between the original dates plus one. This is a release-specific inclusive synthetic day count, not automatically the elapsed actual-day count. Release implementation.

TBILLYIELD(Settlement;Maturity;Price)

• Settlement, Maturity: valid increasing dates.
• Price: positive price per 100 redemption.
• Exactly three arguments. There is no optional Basis parameter; the implementation fixes its date calculation.

The native column contains saved 4.1.16 results; independent references use high-precision arithmetic and the stated source rules. Values are shown to twelve decimal places where needed. Enter DATE expressions directly rather than locale-dependent date text.

For January 1 to April 1, 2024 and Price=98, the helper gives 90 synthetic days, then adds one to make d=91. The yield is (100/98-1)*360/91, approximately 0.080735590940, or 8.0735590940%.

For January 1 to July 1, the corresponding d is 181 and the result is approximately 0.040590821964. A longer holding interval lowers this annualized yield when the purchase and redemption amounts are unchanged.

The numerator is gain divided by the price paid: 2/98 for Price=98. A discount rate would instead use gain divided by redemption, 2/100, so the percentages are not interchangeable even with a shared day count.

At January 1→January 31, 2024, US 30/360 gives 30, then this function adds one to use d=31. TBILLPRICE first advances maturity and then applies 30/360, using 30/360 for that pair. Do not assume the two functions are inverse conversions under a common duration. Their source/native examples distinguish the two operations explicitly.

The source requires Price>0, Settlement<Maturity and d≤360 after adding one. It does not require Price<100; the listed native examples all use 98. Invalid dates, prices and out-of-range durations were not executed.

This formula annualizes a simple holding-period return; it does not compound it or provide a selectable market convention. Verify the intended date basis when reconciling external quotes. The native evidence establishes the eight formulas in this release, not a general claim that its named Treasury-bill function matches another application or pricing standard.

TBILLPRICE, INTRATE, DAYS360.

• Function-specific release implementation
• US 30/360 day adjustment

The generated ODF produced the informational load warning “Not all attributes could be read.” The sheet was hard-recalculated and saved separately. All eight ordinary function identities, inputs and results were reconciled; a stale SUM cache changed from 999999 to 3 and an uncached SUM returned 7. This establishes the stated examples, not every workbook style or invalid input. Other explanatory identities are independent calculations. The authoring-tool XLSX was not executed in OpenOffice, and its preview values are not the native results reported here.