Struct YearFracFn 

pub struct YearFracFn;

Returns the fraction of a year between two dates for a selected day-count basis.

Remarks

• Supported basis values: 0 (US 30/360), 1 (actual/actual), 2 (actual/360), 3 (actual/365), 4 (European 30/360).
• If start_date > end_date, the result is negative.
• Invalid basis values return #NUM!.
• Serial dates are interpreted with the Excel 1900 mapping rather than workbook 1900/1904 context.

Examples

title: "Actual/360 convention"
formula: "=YEARFRAC(44197, 44378, 2)"
expected: 0.5027777778

title: "Actual/365 convention"
formula: "=YEARFRAC(44197, 44378, 3)"
expected: 0.4958904110

related:
  - DAYS360
  - DAYS
  - DATEDIF
faq:
  - q: "How does the basis argument change YEARFRAC?"
    a: "Basis selects the day-count convention (actual or 30/360 variants), so the same dates can yield different fractions."

Trait Implementations

impl Debug for YearFracFn

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Function for YearFracFn

[formualizer-docgen:schema:start] Name: YEARFRAC Type: YearFracFn Min args: 2 Max args: variadic Variadic: true Signature: YEARFRAC(arg1: number@scalar, arg2: number@scalar, arg3…: number@scalar) Arg schema: arg1{kinds=number,required=true,shape=scalar,by_ref=false,coercion=NumberLenientText,max=None,repeating=None,default=false}; arg2{kinds=number,required=true,shape=scalar,by_ref=false,coercion=NumberLenientText,max=None,repeating=None,default=false}; arg3{kinds=number,required=true,shape=scalar,by_ref=false,coercion=NumberLenientText,max=None,repeating=None,default=false} Caps: PURE [formualizer-docgen:schema:end]

fn caps(&self) -> FnCaps

Capability flags for this function

fn name(&self) -> &'static str

fn min_args(&self) -> usize

fn variadic(&self) -> bool

fn arg_schema(&self) -> &'static [ArgSchema]

fn eval<'a, 'b, 'c>( &self, args: &'c [ArgumentHandle<'a, 'b>], _ctx: &dyn FunctionContext<'b>, ) -> Result<CalcValue<'b>, ExcelError>

The unified evaluation path.

fn namespace(&self) -> &'static str

fn volatile(&self) -> bool

fn aliases(&self) -> &'static [&'static str]

Optional list of additional alias names (case-insensitive) that should resolve to this function. Default: empty slice. Implementors can override to expose legacy names. Returned slice must have ’static lifetime (typically a static array reference).

fn function_salt(&self) -> u64

fn eval_reference<'a, 'b, 'c>( &self, _args: &'c [ArgumentHandle<'a, 'b>], _ctx: &dyn FunctionContext<'b>, ) -> Option<Result<ReferenceType, ExcelError>>

Optional reference result path. Only called by the interpreter/engine when the callsite expects a reference (e.g., range combinators, by-ref argument positions, or spill sources).

fn dispatch<'a, 'b, 'c>( &self, args: &'c [ArgumentHandle<'a, 'b>], ctx: &dyn FunctionContext<'b>, ) -> Result<CalcValue<'b>, ExcelError>

Dispatch to the unified evaluation path with automatic argument validation.