Not knowing Celle, but assuming there are a number of SFA in the area, I would say it is due to BFBS's policy on content.
As BFBS2 tends to show more adult orientated programming, stuff that would shown post-watershed in the UK, it is switched off during periods when younger viewers could be at home.
I know it's a nause but, as a parent, I'm glad they have the balls to do this.
Hope this helps.