{ "category": "Financial functions", "display_name": "TBILLPRICE", "entry_kind": "built_in_function", "eval_api": { "method": "POST", "url": "https://handbook.dnacalc.com/api/eval" }, "function_id": "FUNC.TBILLPRICE", "implementation_state": { "answer_bank": { "excel_builds": [ "20430" ], "larger_numeric": 0, "last_bit": 0, "matched": 3600, "other_mismatch": 0, "refused": 0, "rows": 3600, "unread": 0, "worst_ulp": 0 }, "detail": "Recorded: 3,600 in the answer bank and 11 workbook cells.", "dnacalc_commit": "9e1884369a678158dd82d3d74188daf986995e87", "in_catalogue": true, "state": "matches", "state_label": "Matches every recorded Excel answer", "summary": "Matches all 3,611 recorded answers", "workbook_corpus": { "cells": 11, "matched": 11 } }, "implementations": [ { "commit": "9e1884369a678158dd82d3d74188daf986995e87", "flavour": "excel-compatibility-candidate", "language": "Rust", "name": "CalcFunc", "own_code": [ "https://github.com/DnaCalc/DnaCalc/blob/9e1884369a678158dd82d3d74188daf986995e87/crates/calc-func/src/catalogue/bonds.rs#L211-L214", "https://github.com/DnaCalc/DnaCalc/blob/9e1884369a678158dd82d3d74188daf986995e87/crates/calc-func/src/ported/discount_bill_yearfrac_family.rs#L310-L334" ], "repository": "https://github.com/DnaCalc/DnaCalc", "shared_code": [ "catalogue/bonds::bill_arguments", "catalogue/bonds::bill_out", "catalogue/financial::required_number", "catalogue/financial::date_1900", "locale::days_from_civil", "locale::civil_from_days", "locale::excel_serial_from_ymd", "locale::ymd_from_excel_serial", "ported/discount_bill_yearfrac_family::max_excel_serial", "ported/discount_bill_yearfrac_family::parse_date_serial", "ported/discount_bill_yearfrac_family::actual_days", "ported/discount_bill_yearfrac_family::tbill_days", "ported/discount_bill_yearfrac_family::map_discount_bill_yearfrac_error_to_ws" ], "source": "https://github.com/DnaCalc/DnaCalc/blob/9e1884369a678158dd82d3d74188daf986995e87/crates/calc-func/src/catalogue/bonds.rs#L211-L214", "state": "matches", "suite": null, "summary": "Matches all 3,611 recorded answers" } ], "json_url": "https://handbook.dnacalc.com/api/functions/FUNC.TBILLPRICE.json", "name": "TBILLPRICE", "notes": [ { "basis": "8 recorded readings with an empty B1, one per function, each paired with a reading with TRUE in B1.", "documentation": null, "evidence": [ { "commit": "c4c5dde7e2dcf735d2849835fc49769e2ab67ba7", "locator": "delivered_fn4_blank_date_references_read_serial_zero", "note": "recorded answers pinned", "path": "apps/dna-onecalc/tests/acceptance.rs", "repository": "DnaCalc" }, { "commit": "2d0eddcac86413014643af81d646581d54ba57bc", "locator": "sheets qa031 and qa032, and the like pairs of each function", "note": "recorded readings", "path": "crates/calc-func/tests/captures/fn4_questions/functions-fn4-arguments.capture.json", "repository": "DnaCalc" } ], "functions": [ "FUNC.NETWORKDAYS", "FUNC.NETWORKDAYS.INTL", "FUNC.TBILLEQ", "FUNC.TBILLPRICE", "FUNC.TBILLYIELD", "FUNC.WORKDAY", "FUNC.WORKDAY.INTL", "FUNC.YEARFRAC" ], "inferred": null, "kind": "quirk", "note_id": "FN-WORKDAY-001", "open": [ "An argument left empty in the call was not read here for YEARFRAC and the T-bill functions." ], "recorded_on": "2026-11-04", "repros": [ { "call": "=NETWORKDAYS(B1,5)", "correct": null, "excel": { "bits": "0x4010000000000000", "display": "4", "kind": "number" }, "input_route": "cell-value2", "inputs": [ { "name": "B1", "value": { "bits": null, "display": "(empty cell)", "kind": "blank" } } ], "recorded_in": "Excel 16.0.20527.20088 Current Channel, Windows 64-bit (NT 10.0.26200), x86-64, AMD Ryzen 7 4800H, en-ZA", "source": { "commit": "2d0eddcac86413014643af81d646581d54ba57bc", "locator": "sheet qa032, row 20, column 10", "note": null, "path": "crates/calc-func/tests/captures/fn4_questions/functions-fn4-arguments.capture.json", "repository": "DnaCalc" } }, { "call": "=NETWORKDAYS(B1,5)", "correct": null, "excel": { "bits": null, "display": "#VALUE!", "kind": "error" }, "input_route": "cell-value2", "inputs": [ { "name": "B1", "value": { "bits": null, "display": "TRUE", "kind": "logical" } } ], "recorded_in": "Excel 16.0.20527.20088 Current Channel, Windows 64-bit (NT 10.0.26200), x86-64, AMD Ryzen 7 4800H, en-ZA", "source": { "commit": "2d0eddcac86413014643af81d646581d54ba57bc", "locator": "sheet qa031, row 20, column 10", "note": null, "path": "crates/calc-func/tests/captures/fn4_questions/functions-fn4-arguments.capture.json", "repository": "DnaCalc" } }, { "call": "=WORKDAY(B1,2)", "correct": null, "excel": { "bits": "0x4008000000000000", "display": "3", "kind": "number" }, "input_route": "cell-value2", "inputs": [ { "name": "B1", "value": { "bits": null, "display": "(empty cell)", "kind": "blank" } } ], "recorded_in": "Excel 16.0.20527.20088 Current Channel, Windows 64-bit (NT 10.0.26200), x86-64, AMD Ryzen 7 4800H, en-ZA", "source": { "commit": "2d0eddcac86413014643af81d646581d54ba57bc", "locator": "sheet qa054, row 20, column 10", "note": null, "path": "crates/calc-func/tests/captures/fn4_questions/functions-fn4-arguments.capture.json", "repository": "DnaCalc" } }, { "call": "=WORKDAY(B1,2)", "correct": null, "excel": { "bits": null, "display": "#VALUE!", "kind": "error" }, "input_route": "cell-value2", "inputs": [ { "name": "B1", "value": { "bits": null, "display": "TRUE", "kind": "logical" } } ], "recorded_in": "Excel 16.0.20527.20088 Current Channel, Windows 64-bit (NT 10.0.26200), x86-64, AMD Ryzen 7 4800H, en-ZA", "source": { "commit": "2d0eddcac86413014643af81d646581d54ba57bc", "locator": "sheet qa053, row 20, column 10", "note": null, "path": "crates/calc-func/tests/captures/fn4_questions/functions-fn4-arguments.capture.json", "repository": "DnaCalc" } }, { "call": "=NETWORKDAYS.INTL(B1,5,1)", "correct": null, "excel": { "bits": "0x4010000000000000", "display": "4", "kind": "number" }, "input_route": "cell-value2", "inputs": [ { "name": "B1", "value": { "bits": null, "display": "(empty cell)", "kind": "blank" } } ], "recorded_in": "Excel 16.0.20527.20088 Current Channel, Windows 64-bit (NT 10.0.26200), x86-64, AMD Ryzen 7 4800H, en-ZA", "source": { "commit": "2d0eddcac86413014643af81d646581d54ba57bc", "locator": "sheet qa040, row 20, column 10", "note": null, "path": "crates/calc-func/tests/captures/fn4_questions/functions-fn4-arguments.capture.json", "repository": "DnaCalc" } }, { "call": "=WORKDAY.INTL(B1,2,1)", "correct": null, "excel": { "bits": "0x4008000000000000", "display": "3", "kind": "number" }, "input_route": "cell-value2", "inputs": [ { "name": "B1", "value": { "bits": null, "display": "(empty cell)", "kind": "blank" } } ], "recorded_in": "Excel 16.0.20527.20088 Current Channel, Windows 64-bit (NT 10.0.26200), x86-64, AMD Ryzen 7 4800H, en-ZA", "source": { "commit": "2d0eddcac86413014643af81d646581d54ba57bc", "locator": "sheet qa062, row 20, column 10", "note": null, "path": "crates/calc-func/tests/captures/fn4_questions/functions-fn4-arguments.capture.json", "repository": "DnaCalc" } }, { "call": "=YEARFRAC(B1,5,0)", "correct": null, "excel": { "bits": "0x3f8c71c71c71c71c", "display": "0.013888888888888888", "kind": "number" }, "input_route": "cell-value2", "inputs": [ { "name": "B1", "value": { "bits": null, "display": "(empty cell)", "kind": "blank" } } ], "recorded_in": "Excel 16.0.20527.20088 Current Channel, Windows 64-bit (NT 10.0.26200), x86-64, AMD Ryzen 7 4800H, en-ZA", "source": { "commit": "2d0eddcac86413014643af81d646581d54ba57bc", "locator": "sheet qa072, row 20, column 10", "note": null, "path": "crates/calc-func/tests/captures/fn4_questions/functions-fn4-arguments.capture.json", "repository": "DnaCalc" } }, { "call": "=TBILLEQ(B1,5,0.1)", "correct": null, "excel": { "bits": "0x3fb9fddd1b6a757f", "display": "0.10152990264255911", "kind": "number" }, "input_route": "cell-value2", "inputs": [ { "name": "B1", "value": { "bits": null, "display": "(empty cell)", "kind": "blank" } } ], "recorded_in": "Excel 16.0.20527.20088 Current Channel, Windows 64-bit (NT 10.0.26200), x86-64, AMD Ryzen 7 4800H, en-ZA", "source": { "commit": "2d0eddcac86413014643af81d646581d54ba57bc", "locator": "sheet qa082, row 20, column 10", "note": null, "path": "crates/calc-func/tests/captures/fn4_questions/functions-fn4-arguments.capture.json", "repository": "DnaCalc" } } ], "schema": "efh.function-note/v1", "statement": "A reference to an empty cell as the first date of these functions reads as serial 0 and gives a normal answer: NETWORKDAYS(B1,5) is 4 and WORKDAY(B1,2) is 3. YEARFRAC(B1,5,0) is 5/360. TRUE in the same cell gives #VALUE!, as a direct TRUE does, so a blank is not treated as the logical FALSE either.", "status": "measured", "title": "An empty cell as a first date is serial 0, but a logical in that cell is #VALUE!" } ], "schema": "efh.function-reference/v1", "section_order": [ "what-it-does", "try-it", "quirks", "how-to-implement", "version-differences", "alternatives" ], "sections": { "alternatives": "\n[TBILLYIELD](FUNC.TBILLYIELD.md) computes a bill investment yield; [TBILLEQ](FUNC.TBILLEQ.md) computes its specified equivalent yield; [PRICEDISC](FUNC.PRICEDISC.md) accepts a general basis.\n\n\n\n\n", "how-to-implement": "\n1. Coerce the date arguments through the workbook’s date system and truncate their serial values. Validate the discount as finite and positive. Keep the date coercion layer separate: the notes below record a blank reference reading as serial zero, while a logical reference gives `#VALUE!`.\n2. Require settlement before maturity. Convert settlement to year, month and day; construct the next-year date with Excel’s day rollover. Reject maturity beyond that serial date. In the current helper this uses the 1900 date-system conversion functions, including their treatment of Excel’s fictitious leap day.\n3. Let `days=maturity-settlement`. These are actual serial days, without a 30/360 adjustment.\n4. With `D` meaning one nearest/even binary64 rounding, calculate `product=D(discount*days)`, `fraction=D(product/360)`, `remaining=D(1-fraction)`, then `price=D(100*remaining)`. Keep these separate stores and disable contraction into fused operations.\n5. Return `#NUM!` for a nonpositive calculated price; otherwise pass the result through the worksheet’s numeric publisher.\n\nFor the thirty-day example, the mathematical discount fraction is `0.06*30/360=0.005`, so the price is `100*(1-0.005)=99.5`. A discount of twelve over thirty days instead consumes the full face value and reaches the nonpositive-price guard.\n\nThis is the current code’s ordinary binary64 graph. The security functions beside it use other stored arithmetic sites, and [PRICEDISC](FUNC.PRICEDISC.md) subtracts a redemption discount using a different association. An algebraically identical formula does not settle their last bits.\n\n\n", "quirks": "\nDate values are truncated. Invalid dates give `#VALUE!`; a nonpositive discount or an invalid/too-long settlement-to-maturity interval gives `#NUM!`. There is no optional basis argument.\n\nThe one-year limit follows calendar rollover, rather than a fixed 365-day cap or an end-of-month clamp. The cited build-20430 controls admit settlement 29 February 2044 with maturity 1 March 2045, but reject settlement 28 February 1991 with maturity 29 February 1992. The first limit is the result of `DATE(2045,2,29)`, which rolls into March.\n\nThe current helper rejects equal settlement and maturity, and also rejects a calculated price at or below zero. The opened Microsoft remarks explicitly mention settlement later than maturity and nonpositive discount; they do not spell out those two additional guards. A positive discount alone does not ensure a positive price.\n\n\n", "sources": "\n- [Microsoft: TBILLPRICE function](https://support.microsoft.com/en-us/excel/functions/tbillprice-function), opened 6 November 2026; syntax, documented argument rules and errors.\n- [DnaCalc implementation](https://github.com/DnaCalc/DnaCalc/blob/da3ecc4fb19a3a5529708c311d0e8f05688ac165/crates/calc-func/src/ported/discount_bill_yearfrac_family.rs); implementation steps and the limits identified in the text.\n\n", "try-it": "\n`=TBILLPRICE(DATE(2027,1,1),DATE(2027,1,31),0.06)` returns about `99.5`. Thirty days at a six-percent annual discount remove `100*0.06*30/360=0.5` from par.\n\n\n", "version-differences": "The recorded environments below distinguish a reading from a same-input comparison. Counts describe captured inputs in each environment; overlapping captures and comparisons are not totals of unique worksheet calls.\n\n| Excel 16.0 build | Platform and CPU | Captured inputs |\n|---|---|---:|\n| 20430 | Windows, 64-bit, AMD Ryzen 7 4800H with Radeon Graphics | 2,400 |\n\nThe record contains no same-input comparison between these environments. Reading different inputs on different builds does not establish either a version change or cross-build agreement.\n\n[Recorded environments and comparison details](https://github.com/DnaCalc/ExcelFunctionsHandbook/blob/5dc75391aa5125ccc5abdb095da85950980d6fd8/content/evidence/environments/FUNC.TBILLPRICE.json).", "what-it-does": "\n`TBILLPRICE(settlement,maturity,discount)` returns a Treasury bill price per 100 face value using an annual discount rate and an actual-day, 360-day denominator.\n\n\n" }, "signature": { "display": "TBILLPRICE(settlement, maturity, discount)", "parameters": [ { "description": null, "name": "settlement", "optional": false, "repeats": false }, { "description": null, "name": "maturity", "optional": false, "repeats": false }, { "description": null, "name": "discount", "optional": false, "repeats": false } ], "trailing_repeats": false }, "sources": { "metadata": { "admission": { "label": "implemented", "reason": null }, "arity": { "max": 3, "min": 3 }, "category": "Financial functions", "classification": { "arg_preparation_profile": "ValuesOnlyPreAdapter", "coercion_lift_profile": "Custom", "determinism_class": "Deterministic", "error_collapse_profile": "None", "fec_dependency_profile": "None", "host_interaction_class": "None", "kernel_signature_class": "Custom", "rich_value_usage": "RichBlind", "surface_fec_dependency_profile": "None", "thread_safety_class": "SafePure", "volatility_class": "NonVolatile" }, "descriptions": { "long": null, "short": "Treasury bill price per 100 of face value, from its discount rate", "short_source": "dna-calc-own" }, "docs": { "english_description": "Returns the price per $100 face value for a Treasury bill", "microsoft_url": "https://support.microsoft.com/en-us/office/tbillprice-function-eacca992-c29d-425a-9eb8-0513fe6035a2" }, "entry_kind": "built_in_function", "localized_family_names": null, "localized_names": [ { "locale": "ar-SA", "name": "TBILLPRICE" }, { "locale": "bg-BG", "name": "TBILLPRICE" }, { "locale": "cs-CZ", "name": "TBILLPRICE" }, { "locale": "da-DK", "name": "STATSOBLIGATION.KURS" }, { "locale": "de-DE", "name": "TBILLPRICE" }, { "locale": "el-GR", "name": "TBILLPRICE" }, { "locale": "en-AU", "name": "TBILLPRICE" }, { "locale": "en-GB", "name": "TBILLPRICE" }, { "locale": "en-US", "name": "TBILLPRICE" }, { "locale": "es-ES", "name": "LETRA.DE.TES.PRECIO" }, { "locale": "et-EE", "name": "TBILLPRICE" }, { "locale": "fi-FI", "name": "OBLIG.HINTA" }, { "locale": "fr-FR", "name": "PRIX.BON.TRESOR*" }, { "locale": "he-IL", "name": "TBILLPRICE" }, { "locale": "hr-HR", "name": "TBILLPRICE" }, { "locale": "hu-HU", "name": "KJEGY.ÁR" }, { "locale": "id-ID", "name": "TBILLPRICE" }, { "locale": "it-IT", "name": "TBILLPRICE" }, { "locale": "ja-JP", "name": "TBILLPRICE" }, { "locale": "ko-KR", "name": "TBILLPRICE" }, { "locale": "lt-LT", "name": "TBILLPRICE" }, { "locale": "lv-LV", "name": "TBILLPRICE" }, { "locale": "nb-NO", "name": "TBILLPRIS" }, { "locale": "nl-NL", "name": "SCHATK.PRIJS" }, { "locale": "pl-PL", "name": "CENA.BS" }, { "locale": "pt-BR", "name": "TBILLPRICE" }, { "locale": "pt-PT", "name": "OTNVALOR" }, { "locale": "ro-RO", "name": "TBILLPRICE" }, { "locale": "ru-RU", "name": "ЦЕНАКЧЕК" }, { "locale": "sk-SK", "name": "TBILLPRICE" }, { "locale": "sl-SI", "name": "TBILLPRICE" }, { "locale": "sr-Latn-RS", "name": "TBILLPRICE" }, { "locale": "sv-SE", "name": "SSVXPRIS" }, { "locale": "th-TH", "name": "TBILLPRICE" }, { "locale": "tr-TR", "name": "HTAHDEĞER işlevi" }, { "locale": "uk-UA", "name": "TBILLPRICE" }, { "locale": "vi-VN", "name": "TBILLPRICE" }, { "locale": "zh-CN", "name": "TBILLPRICE" }, { "locale": "zh-HK", "name": "TBILLPRICE" }, { "locale": "zh-TW", "name": "TBILLPRICE" } ], "signature": { "display": "TBILLPRICE(settlement, maturity, discount)", "parameters": [ { "description": null, "name": "settlement", "optional": false, "repeats": false }, { "description": null, "name": "maturity", "optional": false, "repeats": false }, { "description": null, "name": "discount", "optional": false, "repeats": false } ], "trailing_repeats": false }, "surface_name": "TBILLPRICE", "version_marker": null, "xlcall": { "code": "439", "symbol": "xlfTbillprice" } }, "microsoft": "https://support.microsoft.com/en-us/office/tbillprice-function-eacca992-c29d-425a-9eb8-0513fe6035a2" }, "try_it": { "formula": "=TBILLPRICE(DATE(2027,1,1),DATE(2027,1,31),0.06)" }, "url": "https://handbook.dnacalc.com/functions/TBILLPRICE.html", "variants": [], "versions": [ { "behaviour": "2,400 captured inputs are indexed for this environment. Capture dates: 2026-09-24 to 2026-09-25. This is a reading count, not a comparison with another build.", "excel_build": "16.0 build 20430", "platform": "Windows, 64-bit, AMD Ryzen 7 4800H with Radeon Graphics", "sources": [ "https://github.com/DnaCalc/ExcelFunctionsHandbook/blob/5dc75391aa5125ccc5abdb095da85950980d6fd8/content/evidence/environments/FUNC.TBILLPRICE.json" ] } ] }