Hi there Steve,
Thanks for reaching out and sorry for the delay in my reply! I assigned this issue to myself but lost track of it until now…
I’m not really familiarized with how gridbuilder shortcodes are actually coded, you’ll have to reach out to their developers to get help.
From what I see I guess you are not getting the desired result because $post might not be set to the current event you are trying to output the date for. If the first parameter is null the function will try to get the current post object. Also, when you pass the parameters to the function there’s no need to declare the variable name:
echo tribe_get_start_date(null, false, 'g:i a' );
Hope that helps,
Best,
Nico