Function cron

packages/effect/src/Schedule.ts:681–693

(expression: string | Cron.Cron, tz?: string | DateTime.TimeZone)

  (expression: Cron.Cron): Schedule<Duration.Duration, unknown, Cron.CronParseError>
  (expression: string, tz?: string | DateTime.TimeZone): Schedule<Duration.Duration, unknown, Cron.CronParseError>
} = (expression: string | Cron.Cron, tz?: string | DateTime.TimeZone) => {
  const parsed = Cron.isCron(expression) ? Result.succeed(expression) : Cron.parse(expression, tz)
  return fromStep(effect.map(effect.fromResult(parsed), (cron) => (now, _) => {
    if (now === Number.POSITIVE_INFINITY) {
      return Cause.done(Duration.zero)
    }
    return effect.sync(() => {
      const next = Cron.next(cron, now).getTime()
      const duration = Duration.millis(next - now)
      return [duration, duration]
    })
  }))
}

/**
 * Returns a schedule that recurs once after the specified duration.