Good evening Paul and welcome to the Events Calendar forum!
Thank you for your interest in our products.
We’ll be glad to answer your questions.
I’m wondering if I can upload Gigpress content from one site to The Events Calendar on another site.
The short answer is yes. You can totally achieve that.
The way to do this is to export your Gigpress calendar in CSV format using Gigpress > Import/Export. Once that is done you can simply use the Events Calendar’s built-in Import CSV feature.
You can read about this here: https://theeventscalendar.com/gigpress-with-the-events-calendar-and-event-tickets/
Let me know if that helps.
Have a great day!
Geoff B.