What date do the cancellation tickets go on re-sale for Glastonbury 2010?

I persuaded my Dad and his wife that we should all go to Glastonbury next year as it’s the 40th Anniversary, me and my wife have been several times (never together) but my Dad and his wife have never been. Anyway my Dad and his wife got tickets, arranged campervan hire (with toilet!!) and me and the wife completely forgot about it! They of course sold out in one day, Doh! I really don’t want to let him down as he really wants us to be there with them so I need to know when the next batch of tickets go on sale (I think it’s in spring) so I can book the day off work and spend it on the internet frantically hitting F5 and trying to buy our tickets.

Anyone know the exact date?