DERNIER JOUR DU MOIS, OU DE LA SEMAINE

CREATE FUNCTION [dbo].[Last_Day] (@date AS datetime) 
RETURNS datetime
AS
BEGIN
	set @date = DATEADD(DAY, 1-DAY(@date), @date)
	set @date = DATEADD(MONTH, 1, @date)
	return DATEADD(DAY, -1, @date)
END


CREATE FUNCTION [Last_Week_Day] (@date AS datetime) 
RETURNS datetime
AS
BEGIN
	return DATEADD(DAY, 7-DatePart(DW, @date), @date)
END


CREATE FUNCTION [IsLeapYear] (@Annee AS int) 
RETURNS bit
AS
BEGIN
	Declare @Date29Fev AS Datetime
	Declare @Result AS bit
	SET @Date29Fev  = DATEADD(DAY, -1, Cast('01/03/'+Cast(@Annee AS varchar(4)) AS datetime))
	IF Day(@Date29Fev )=29	
		SET @Result =1
	ELSE
		SET @Result = 0

	return @Result
END