After a long day at work I'm back. I was hoping this wouldn't have reached thread two.
Re: nursery, In England at least, when a child gets to three years old, they get a certain number of free hours a week at nursery. If parents don't go out to work, children will often be at home with their mother or father until the free nursery time comes into action, then they might go to nursery for their free hours to learn social skills with other children and to prepare them for school. I believe the free hours aren't that many (maybe 5 hours a week) although this may be higher or lower in Scotland as England and Scotland differ on a few things like this.
It is possible that M's mother had him booked in at nursery for only the free hours so he may only have a place for a morning or two a week. If this is the case and the nursery went back on Jan 7th, then he hasn't actually missed that much. If he went on a Thursday and Friday for example, this year it would only have been two sessions he had missed before the date we believe he went missing.