DECLARE	@Var0 datetime
,	@Var1 datetime
,	@Var2 datetime
,	@Var3 datetime;

SELECT	@Var0 = '01/01/2010'
,	@Var1 = '1900-01-03 00:00:00.000'
,	@Var2 = '1900-01-03 11:00:00.000'
,	@Var3 = 2;

SELECT CAST(CAST(@Var1 AS decimal(38,19)) + CAST(@Var0 AS decimal(38,19)) AS datetime);
SELECT CAST(@Var1 AS decimal(38,19)), CAST(@Var0 AS decimal(38,19));

SELECT CAST(CAST(@Var2 AS decimal(38,19)) + CAST(@Var0 AS decimal(38,19)) AS datetime);
SELECT CAST(@Var2 AS decimal(38,19)), CAST(@Var0 AS decimal(38,19));

SELECT CAST(CAST(@Var3 AS decimal(38,19)) + CAST(@Var0 AS decimal(38,19)) AS datetime);
SELECT CAST(@Var3 AS decimal(38,19)), CAST(@Var0 AS decimal(38,19));