When you book, your booking will be for the next class up - want to book in advance? Simply fill in your desired date in the ‘anything I should know’ box that appears at checkout. You can book maximum 1 month in advance. When you book, your booking will be for the next class up - want to book in advance? Simply fill in your desired date in the ‘anything I should know’ box that appears at checkout. You can book maximum 1 month in advance.