presto-main/src/main/java/io/prestosql/operator/scalar/FormatFunction.java/FormatFunction/toZonedDateTime
class FormatFunction:    private static ZonedDateTime toZonedDateTime(long value)
    {
        Instant instant = Instant.ofEpochMilli(unpackMillisUtc(value));
        ZoneId zoneId = ZoneId.of(unpackZoneKey(value).getId());
        return ZonedDateTime.ofInstant(instant, zoneId);
    }