In the school calendar for the term, which the boys ( and parents ) were given at start of term, it has 29th of January published as last day of interviews. Although they did request help until the 31st as Croydonmum has said. It is not unusual for them to request an for an extra couple of days, in case they need to add more days on, if people can't make appointments, bad weather ( as we've had last couple of years) etc.