convert local time to utc time

USE [Gamyam]
GO
/****** Object: UserDefinedFunction [dbo].[convertutcdatetime] Script Date: 9/8/2016 12:06:05 PM ******/
SET ANSI_NULLS ON
GO
SET QUOTED_IDENTIFIER ON
GO

ALTER FUNCTION [dbo].[convertutcdatetime]()
RETURNS datetime
AS
BEGIN
DECLARE @ret datetime;
declare @Diff nvarchar(20)
select @Diff=TimeZone from Country
SELECT @ret = convert(Datetime,switchoffset (CONVERT(datetimeoffset, GETUTCDATE()),@Diff));

RETURN @ret;
END;