Date reservation full up

Hi we have been using a form - Early Booking Discount Form for a few months very succesfully but the calendar seems to be full now - customers are unable to choose any dates until December. There shouldn't be any restrictions on how many times dates can be chosen - can you help please?

I can see you have already opened a thread for this, please check the response you have received on the other thread and post your follow up replies here: https://www.jotform.com/answers/1609881 

Thanks.