The two days have been swapped - or maybe I just got them in the wrong order when I posted!
http://www.eastmidlandstrains.co.uk/AboutUs/News/Pages/_FestiveRedDotDays.aspx
Festive Red Dot Days for Sheffield and Nottingham
Article posted on 09/12/2010
Travel anywhere for just £15
Discover all there is to see and do on the East Midlands Trains network with our fantastic Red Dot Days. We are offering unlimited travel from Sheffield on Wednesday 29 December and Nottingham on Thursday 30 December to anywhere on the East Midlands Trains network, including London, for just £15 (£5 for children).
To take advantage of these special offers, all you have to do is download the voucher form below. Print your voucher, complete the fields and present it at the station when you buy your tickets. (Multiple tickets can be bought with one voucher.) Ask about our seat reservations to guarantee a seat, then simply turn up and go.