How to Add multiple instance of meta box to custom post type

I am able to make custom post type and custom meta box but my situation is that i want to attach multiple instance of custom meta box to custom post type.

my custom post type is show which have custom fields like start date,link,venue lets call it showinfo

now for every show i can have multiple showinfo

so how to achieve that

in attached image see show events time box in right middle side of picture that better explain what i am asking