Function getUtcForZonedTime

common/src/util/zoned-time.ts:50–80

(
  parts: Pick<ZonedDateParts, 'year' | 'month' | 'day'>,
  timeZone: string,
  hour: number,
  minute: number,
)

}

export function getUtcForZonedTime(
  parts: Pick<ZonedDateParts, 'year' | 'month' | 'day'>,
  timeZone: string,
  hour: number,
  minute: number,
): Date {
  let guess = new Date(
    Date.UTC(parts.year, parts.month - 1, parts.day, hour, minute),
  )

  for (let i = 0; i < 3; i++) {
    const actual = getZonedParts(guess, timeZone)
    const desiredUtc = Date.UTC(
      parts.year,
      parts.month - 1,
      parts.day,
      hour,
      minute,
    )
    const actualUtc = Date.UTC(
      actual.year,
      actual.month - 1,
      actual.day,
      actual.hour,
      actual.minute,
    )
    guess = new Date(guess.getTime() + (desiredUtc - actualUtc))
  }

  return guess
}

export function getZonedDayBounds(
  now: Date,