Calcular a data da páscoa, Paixão de Cristo e Carnaval

feriados_moveis.sql

/*Busca via WS a data da Páscoa de cada ano e calcula o carnaval, Paixão de Cristo e Corpus Christi entre 2019 e 2029*/
SELECT ANO
      ,PASCOA
      ,PASCOA - 47 AS CARNAVAL
      ,PASCOA - 2 AS PAIXAO_DE_CRISTO
      ,PASCOA + 60 AS CORPUS_CHRISTI
  FROM (SELECT 2000 + LEVEL AS ANO
              ,CAST(TO_TIMESTAMP_TZ(EXTRACTVALUE(HTTPURITYPE('www.holidaywebservice.com/Holidays/GBSCT/Dates/GBSCTHolidayDates.asmx/GetEaster?year=' || TO_CHAR(2000 + LEVEL))
                                                 .GETXML(),
                                                 '/dateTime',
                                                 'xmlns="http://www.27seconds.com/Holidays/GBSCT/Dates/"'),
                                    'YYYY-MM-DD"T"HH24:MI:SS.FF7TZH:TZM') AS DATE) AS PASCOA
          FROM DUAL
        CONNECT BY LEVEL BETWEEN 1 AND 29)
 WHERE ANO >= 2019