Class CronCalculator

Computes next/previous scheduled run times for cron expressions.

Index

Constructors

Properties

formatter instance? parser

Methods

build DOM DOW getPart lower match next parts pick prev resolve run step toDateTimeParts upper valid getInstance

Constructors

`Private`constructor

new CronCalculator(): CronCalculator
Returns CronCalculator
- Defined in calculator.ts:22

Properties

`Private` `Readonly`formatter

formatter: Map<string, DateTimeFormat> = ...

`Private` `Static` `Optional`instance

instance?: CronCalculator

`Private` `Static` `Readonly`parser

parser: CronParser = ...

Methods

`Private`build

build(
    year: number,
    month: number,
    day: number,
    hour: number,
    minute: number,
    tz: string,
): Date
Build UTC Date from timezone-aligned components.
Parameters
- year: number
- month: number
- day: number
- hour: number
- minute: number
- tz: string
Returns Date
- Defined in calculator.ts:138

`Private`DOM

DOM(year: number, month: number): number
Get number of days in month.
Parameters
- year: number
- month: number
Returns number
- Defined in calculator.ts:30

`Private`DOW

DOW(year: number, month: number, day: number): number
Get the day of week.
Parameters
- year: number
- month: number
- day: number
Returns number
- Defined in calculator.ts:35

`Private`getPart

getPart(parts: DateTimeFormatPart[], key: string): number
Get date time part by key.
Parameters
- parts: DateTimeFormatPart[]
- key: string
Returns number
- Defined in calculator.ts:122

`Private`lower

lower(arr: readonly number[], x: number): number
Binary search: lower bound (first >= x).
Parameters
- arr: readonly number[]
- x: number
Returns number
- Defined in calculator.ts:40

`Private`match

match(parsed: ParsedCronExpression, dom: number, dow: number): boolean
Cron day matching logic (DOM + DOW semantics).
Parameters
- parsed: ParsedCronExpression
- dom: number
- dow: number
Returns boolean
- Defined in calculator.ts:92

next

next(expr: CronInput, options?: RunOptions): Date[]
Compute next N execution times.
Parameters
- expr: CronInput
  Cron string or pre-parsed expression
- options: RunOptions = {}
  Run options (timezone, before, after, count)
Returns Date[]
Example
```
calc.next( '0 9 * * MON', { count: 3, timezone: 'UTC' } );
```
- Defined in calculator.ts:230

`Private`parts

parts(date: Date, tz: string): DateParts
Extract timezone-safe date parts.
Parameters
- date: Date
- tz: string
Returns DateParts
- Defined in calculator.ts:127

`Private`pick

pick(
    arr: readonly number[],
    min: number,
    max: number,
    cur: number,
    lvl: boolean,
    dir: -1 | 1,
): readonly number[]
Returns only the relevant candidates using binary search jumps. No full array scans, no filtering, no allocation loops.
Parameters
- arr: readonly number[]
- min: number
- max: number
- cur: number
- lvl: boolean
- dir: -1 | 1
Returns readonly number[]
- Defined in calculator.ts:69

prev

prev(expr: CronInput, options?: RunOptions): Date[]
Compute previous N execution times.
Parameters
- expr: CronInput
  Cron string or pre-parsed expression
- options: RunOptions = {}
  Run options (timezone, before, after, count)
Returns Date[]
Example
```
calc.prev( '0 9 * * MON', { count: 3 } );
```
- Defined in calculator.ts:243

`Private`resolve

resolve(input: CronInput): ParsedCronExpression
Resolve string or parsed expression into ParsedCronExpression.
Parameters
- input: CronInput
Returns ParsedCronExpression
- Defined in calculator.ts:25

`Private`run

run(expr: CronInput, opt: RunOptions, dir: -1 | 1): Date[]
Shared execution loop for next/prev.
Parameters
- expr: CronInput
- opt: RunOptions
- dir: -1 | 1
Returns Date[]
- Defined in calculator.ts:201

`Private`step

step(
    parsed: ParsedCronExpression,
    from: Date,
    tz: string,
    dir: -1 | 1,
): Date | null
Core jump-based scheduler. Walks year → month → day → hour → minute using binary search jumps.
Parameters
- parsed: ParsedCronExpression
- from: Date
- tz: string
- dir: -1 | 1
Returns Date | null
- Defined in calculator.ts:153

`Private`toDateTimeParts

toDateTimeParts(tz: string, date: Date): DateTimeFormatPart[]
Format a date into timezone-aligned parts.
Parameters
- tz: string
- date: Date
Returns DateTimeFormatPart[]
- Defined in calculator.ts:111

`Private`upper

upper(arr: readonly number[], x: number): number
Binary search: upper bound (last <= x).
Parameters
- arr: readonly number[]
- x: number
Returns number
- Defined in calculator.ts:53

`Private`valid

valid(
    year: number,
    month: number,
    day: number,
    hour: number,
    minute: number,
    p: DateParts,
    dir: -1 | 1,
): boolean
Validate chronological direction correctness.
Parameters
- year: number
- month: number
- day: number
- hour: number
- minute: number
- p: DateParts
- dir: -1 | 1
Returns boolean
- Defined in calculator.ts:100

`Static`getInstance

getInstance(): CronCalculator
Get the CronCalculator instance.

Returns CronCalculator
- Defined in calculator.ts:18