[[ISODate]], _item_.[[Calendar]]).
          1. If _item_ has an [[InitializedTemporalZonedDateTime]] internal slot, then
            1. Let _isoDateTime_ be GetISODateTimeFor(_item_.[[TimeZone]], _item_.[[EpochNanoseconds]]).
            1. Let _resolvedOptions_ be ? GetOptionsObject(_options_).
            1. Perform ? GetTemporalOverflowOption(_resolvedOptions_).
            1. Return ! CreateTemporalDate(_isoDateTime_.[[ISODate]], _item_.[[Calendar]]).
          1. If _item_ has an [[InitializedTemporal