SET ANSI_NULLS ON
GO
 
SET QUOTED_IDENTIFIER ON
GO
 
-- =============================================
-- Author:      Insus.NET
-- Create date: 2019-05-14
-- Update date: 2019-05-14
-- Description: 判断是否为闰年
-- =============================================
 
CREATE FUNCTION [dbo].[svf_IsLeapYear] ( 
    @Year INT
)
RETURNS BIT
AS
BEGIN
    DECLARE @rtv BIT = 0,
            @February_1st DATETIME = CAST((CAST(@Year AS NVARCHAR(4)) + N'-02-01') AS DATETIME)
    
    --IF DAY([dbo].[svf_LastDayOfTheMonth](@February_1st)) = 29
    IF DAY(DATEADD(DAY,-1,DATEADD(MONTH,DATEDIFF(MONTH,0,@February_1st) + 1,0))) = 29
 
        SET @rtv = 1
    RETURN @rtv
END
GO