Last time I was there they said that Knowth is now open all year round (I think). As Cian said, at this time of year you should have no problem getting in on a tour. As much as I dislike the 'Newgrange experience', everyone should go there once.
Last time I was there they said that Knowth is now open all year round (I think).
Last year it definitely did close though I had heard from other people that it wouldn't. I'm going to contact the centre to see if I can hang around inside until they lock the gates at the end of the month, sunset is around 6pm then and they usually stay until 6.30 or so.