Essential maintenance work BBC1 + 2

At the end of Look North Leeds last night, the presenter warned programmes may be affected on BBC1 and 2 in the early hours of this Sunday, Monday and Tuesday due to essential maintenance work. Just out of interest, can anyone shed any further light on this? Is it just a problem in this region and will it affect anyone regardless of which transmitter they're on?

I'm guessing it's work being carried out on the Emley Moor transmitter, hence why it was mentioned on a local news bulletin rather than a national one.