Cálculo de Feriados Móveis

Seguindo regras de cálculos já bastante conhecidas na internet, segue implementação em SQLServer dos feriados móveis no Brasil.


Declare @ano int

Set @ano = 2009

DECLARE
@seculo INT,
@G INT,
@K INT,
@I INT,
@H INT,
@J INT,
@L INT,
@MesDePascoa INT,
@DiaDePascoa INT,
@pascoa smalldatetime


SET @seculo = @ano / 100
SET @G = @ano % 19
SET @K = ( @seculo - 17 ) / 25
SET @I = ( @seculo - CAST(@seculo / 4 AS int) - CAST(( @seculo - @K ) / 3 AS int) + 19 * @G + 15 ) % 30
SET @H = @I - CAST(@I / 28 AS int) * ( 1 * -CAST(@I / 28 AS int) * CAST(29 / ( @I + 1 ) AS int) ) * CAST(( ( 21 - @G ) / 11 ) AS int)
SET @J = ( @ano + CAST(@ano / 4 AS int) + @H + 2 - @seculo + CAST(@seculo / 4 AS int) ) % 7
SET @L = @H - @J
SET @MesDePascoa = 3 + CAST(( @L + 40 ) / 44 AS int)
SET @DiaDePascoa = @L + 28 - 31 * CAST(( @MesDePascoa / 4 ) AS int)
SET @pascoa = CAST(@MesDePascoa AS varchar(2)) + '-' + CAST(@DiaDePascoa AS varchar(2)) + '-' + CAST(@ano AS varchar(4))


Select @pascoa as 'Pascoa',
DateAdd(dd, -3, @pascoa) as 'Sexta-Feira Paixao',
DateAdd(dd, -47, @pascoa) as 'Quarta Carnaval',
DateAdd(dd, 60, @pascoa) as 'CORPUS CHRISTI'