The settings are generally random. The tournament host usually picks. The actual people FIGHTING don't, ever. Keeps them honest. 

So if we do one in May, that means around 3 a year. So the next one, and last one of the year, will take place in Sept. 

Jan. 
May. 
September. 
Jan. 
May. 
Sept. 

otherwise it would be. 

Jan. 
April. 
July.  
Oct. 

As the tournaments take place in a calender year.