Time travel to now

Student movie style time machine is tried in a room. The students open the door and find themselves sleeping in a smelly cave with a donkey and sheep and people speaking a foreign language. (Just finished reading Living in Caves of the Chevron Mountains, by Jacob Habakuk) They have all kinds of adventures and get back to our time.

On the next try they land in Equatorial Ginea, but on the side that has no access to modernity. Then they meet some tribes deep in the forests of Brazil. They land on an island with strange animals that they didn't know existed in National Geographic. In several cases they land in strange cults, like strange religious cults in Asia and Africa, or religious groups in Central America and in the USA. Surprisingly the students can talk their language and understand their culture, which is discussed during the episode.

In each episode they come out fully dressed (or undressed) for the part, and accumulate proof that they were actually there.

Each episode ends with them discovering that actually they went slightly FORWARD in time just a day or two. And that they are still in (more than less) the current time, when they suddenly see modern buildings cars or gadgets like phones. Sometimes what fooled them till the end are old watches that people wear in this place, or the use of old cars.

They keep on trying to fix the machine, and much time is spent trying to calculate if they moved forward or backwards in time, and which time zone they visited last time.