Yes I would say from date of entry, as they are living here with a close tie
Edit: Just to amend slightly, it seems that there is a setteld purpose for coming to the UK but as there may be more to this than first meets the eye, I am only making a general comment. It may be worth talking to HMRC about the status.
-- Edited by Wella on Sunday 15th of April 2012 03:23:07 PM