They were telling us this while we were at a campground.
It is Biblically mandated of observant Jews; they move out of their houses into temporary shelters once every year to remind themselves of the 40 years in the wilderness in tents - also called 'booths' or 'tabernacles'.
I presume that the Jews that you talked to were non-observant Jews - NOT speaking for all Jews. 🤷♂️