Function ToLocalTime

packages/ecma402-abstract/DateTimeFormat/ToLocalTime.ts:135–183

(
  t: Decimal,
  calendar: string,
  timeZone: string,
  {tzData}: ToLocalTimeImplDetails
)

 * @param timeZone
 */
export function ToLocalTime(
  t: Decimal,
  calendar: string,
  timeZone: string,
  {tzData}: ToLocalTimeImplDetails
): {
  weekday: number
  era: string
  year: number
  relatedYear: undefined
  yearName: undefined
  month: number
  day: number
  hour: number
  minute: number
  second: number
  millisecond: number
  inDST: boolean
  timeZoneOffset: number
} {
  invariant(
    calendar === 'gregory',
    'We only support Gregory calendar right now'
  )
  const [timeZoneOffset, inDST] = getApplicableZoneData(
    t.toNumber(),
    timeZone,
    tzData
  )

  const tz = t.plus(timeZoneOffset).toNumber()
  const year = YearFromTime(tz)
  return {
    weekday: WeekDay(tz),
    era: year < 0 ? 'BC' : 'AD',
    year,
    relatedYear: undefined,
    yearName: undefined,
    month: MonthFromTime(tz),
    day: DateFromTime(tz),
    hour: HourFromTime(tz),
    minute: MinFromTime(tz),
    second: SecFromTime(tz),
    millisecond: msFromTime(tz),
    inDST,
    // IMPORTANT: Not in spec
    timeZoneOffset,
  }
}