They didnt vote on a date! They voted on Striking I cant find any reference to 18th. Members of the Unite union supported industrial action by a ratio of more than nine to one, on a 38% turnout. The union is seeking the bonus, which will cost ?14m, for the 20,000 bus workers it represents, claiming that all other transport workers are being paid a premium for working during the event. At least 800,000 extra passengers are predicted on buses during the Olympics. The ballot allows the union to name a date for a strike, but it has yet to do so. Unite said it was giving the 21 bus companies a final opportunity to consider the "landslide" ballot result before announcing possible strike dates early this week.