How long does it take to build something like this in minecraft?

How long does it take approximately?

I once built something like that with a friend, well it took me 3 hours but was creative with Worldeddit

This is mostly done with mods if you really want to build something like that, it takes 1 day if you are fast

30 min.

If you look closely, the main frame is a rectangle with further rectangles.

Well I think it depends on your building experience but I think maybe 4 hours alone without Worldedit

Hi. I have built this and it took me like 5 hours to build this