The safest way is to use DatePart:
WHERE DATEPART(year, demodate)=DATEPART(year, GETDATE()) AND DATEPART(dy, demodate)=DATEPART(dy, GETDATE())
This returns only records where the year and day of year are the same - be aware that if you should read GETDATE once, and store it, as otherwise is may cause intermittent errors around new year!