types.ts

export type DatePartName =
  | 'weekday'
  | 'year'
  | 'month'
  | 'lmonth'
  | 'day'
  | 'dayPeriod'
  | 'hour'
  | 'lhour'
  | 'minute'
  | 'second'

export type DateParts = { [k in DatePartName]: string }

export type Token = { type: DatePartName | 'literal'; value: string }

export type Parser = (date: Date) => DateParts

export type FormatterMask =
  | 'YYYY'
  | 'YY'
  | 'MMMM'
  | 'MMM'
  | 'MM'
  | 'DD'
  | 'dddd'
  | 'ddd'
  | 'A'
  | 'a'
  | 'HH'
  | 'hh'
  | 'mm'
  | 'ss'

export type Formatter = (tokens: DateParts, date: Date) => string

export type Formatters = { [k in FormatterMask]: Formatter }

export type CustomFormatters = { [k: string]: Formatter }

export type FormatFunction = (date: Date, format: string, options?: FormatOptions) => string

export type FormatOptions = {
  locale?: string
  timezone?: string
}