http://www.aa.net.uk/news-2012-christmas.html
We are pleased to confirm that customers on our standard units based tariffs will again benefit from a Christmas special rate between Christmas and New Year.
The three normal working days between Christmas and New Year will be a Christmas special rate which consumes no units regardless of the amount of usage. That is 27th Dec, 28th Dec, and 31st Dec. The 29th Dec and 30th Dec being normal Weekend rates. The 25th Dec, 26th Dec, 1st Jan, and (for lines in Scotland) 2nd Jan, are the new Holiday rate (same usage levels as weekends).
Customers on our new Home::1 tariff (which we expect to have launched by then) have usage allowances that can be used any time of day and day of the year, so there is no special rate for Christmas. However, we will be adding an extra 3GB to your December monthly quota on Christmas morning.
Merry Christmas and a Happy New Year from all at A&A