Date and time functions

This page lists the 25 functions of the date and time family. Taxonomy/source: Date and time functions. The formula function contract has every family, the engine builds, and the evaluation limits.

Functions

Signature profiles

Argument order, required/default state, accepted shapes, repetition, and return shape come directly from the inventory.

Signature: date-three

Return shape: scalar.

Argument	Required	Default	Accepts	Repetition
part1	yes	none	scalar, reference	once
part2	yes	none	scalar, reference	once
part3	yes	none	scalar, reference	once

Signature: unary-value

Return shape: scalar.

Argument	Required	Default	Accepts	Repetition
value	yes	none	scalar, range, array, reference	once

Signature: unary-number

Return shape: scalar.

Argument	Required	Default	Accepts	Repetition
number	yes	none	scalar, reference	once

Signature: zero

Return shape: scalar.

Argument	Required	Default	Accepts	Repetition
none	—	—	—	—

Signature: date-pair

Return shape: scalar.

Argument	Required	Default	Accepts	Repetition
endDate	yes	none	scalar, reference	once
startDate	yes	none	scalar, reference	once

Signature: date-offset

Return shape: scalar.

Argument	Required	Default	Accepts	Repetition
startDate	yes	none	scalar, reference	once
offset	yes	none	scalar, reference	once

Signature: weekday-weeknum

Return shape: scalar.

Argument	Required	Default	Accepts	Repetition
serialNumber	yes	none	scalar, reference	once
returnType	no	1	scalar, reference	once

Signature: workday

Return shape: scalar.

Argument	Required	Default	Accepts	Repetition
startDate	yes	none	scalar, reference	once
days	yes	none	scalar, reference	once
holidays	no	none	range, array, reference	once

Signature: networkdays

Return shape: scalar.

Argument	Required	Default	Accepts	Repetition
startDate	yes	none	scalar, reference	once
endDate	yes	none	scalar, reference	once
holidays	no	none	range, array, reference	once

Signature: yearfrac-days360

Return shape: scalar.

Argument	Required	Default	Accepts	Repetition
startDate	yes	none	scalar, reference	once
endDate	yes	none	scalar, reference	once
basisOrMethod	no	0	scalar, reference	once

Signature: datedif

Return shape: scalar.

Argument	Required	Default	Accepts	Repetition
startDate	yes	none	scalar, reference	once
endDate	yes	none	scalar, reference	once
unit	yes	none	scalar, reference	once

Signature: calendar-intl

Return shape: scalar.

Argument	Required	Default	Accepts	Repetition
startDate	yes	none	scalar, reference	once
endDateOrDays	yes	none	scalar, reference	once
weekend	no	1	scalar, reference	once
holidays	no	none	scalar, range, array, reference	once

Semantic profiles

These values are normative for the listed Sheetwrite subset. function-defined and contextual are explicit limitations: consult the formula guides' function-specific sections rather than assuming another spreadsheet's edge behavior.

Semantics: date-time

Dimension	Contract
shape	scalar: accepted range: contextual array: contextual broadcast: function-defined result: scalar
coercion	blank: zero text: number-if-parseable boolean: number error: propagate
text	case: insensitive wildcard: literal
environment	locale: invariant dateSystem: excel-1900
numeric	tolerance: binary64 domain: bounded iteration: kind: none maximum: none
calculation	dependencies: tracked lazy: eager spill: scalar fill: relative-reference-rewrite copy: relative-reference-rewrite structuralRewrite: ast-reference-rewrite
persistence	snapshot: formula-source history: formula-source collaboration: formula-source xlsxSource: rewrite-on-structural-edit

Semantics: volatile-date

Dimension	Contract
shape	scalar: accepted range: rejected array: rejected broadcast: none result: scalar
coercion	blank: preserved text: preserved boolean: preserved error: propagate
text	case: not-applicable wildcard: not-applicable
environment	locale: not-applicable dateSystem: host-clock
numeric	tolerance: binary64 domain: bounded iteration: kind: none maximum: none
calculation	dependencies: none lazy: not-applicable spill: scalar fill: source-preserved copy: source-preserved structuralRewrite: source-preserved
persistence	snapshot: formula-source history: formula-source collaboration: formula-source xlsxSource: rewrite-on-structural-edit

Dialect profiles

Dialect: excel-documented

Dialect	Status
Microsoft Excel	documented
Google Sheets	unverified
OpenFormula	unverified

Limitations: Google Sheets and OpenFormula results require producer evidence before compatibility is claimed.

Implementation profiles

Implementation: implemented-assisted

Layer	Status and source/evidence
Parser	implemented packages/wasm/src/calc.rs
Evaluator	implemented packages/wasm/src/eval/mod.rs packages/wasm/src/eval/functions.rs
Formula assist	implemented packages/core/src/formula-assist.ts
Evidence	source-linked packages/wasm/src/tests.rs packages/core/test/formula-assist.test.ts

Implementation: analysis-dates

Layer	Status and source/evidence
Parser	implemented packages/wasm/src/calc.rs
Evaluator	implemented packages/wasm/src/eval/analysis/dates.rs
Formula assist	implemented packages/core/src/formula-assist.ts
Evidence	source-linked scripts/formula-contract.test.ts