A lot depends on the amount of piggies that you have, and the size of their cage.
As my guinea pigs have always had cages well over the maximum recommended size I usually aim for floor time once a week.
Their floor time pen isn't much larger than their actual cages, so it was more about a change of scenery and a chance for me to do a full cage clean without them bouncing around and nipping me (Ruby).
I have a 2x6 cage but they’d rather run around on the floor, I let the piggies tell me when they’ve had enough (Bruno usually flopped on the floor and ozzy in a tunnel) we usually get about 40 minutes to an hour before they’re done. I’d say they’re out around 5 times a week
My lot go in the run every day, have fun in there all day and then they go back in the hutch at night. I change what is in the run every few days so there is always something new for them to explore. Atm they are still going through solidifying their new bond so I have to have open ended tunnels and paper bags that have their closed end opened up so that no piggie gets trapped. When the bonding is complete in 7 days they can have all the fun things back like cardboard boxes, carrot cottages, the fleece forest and snuggle sacks.
My boys are out for 3 hours every day except every fourth day when I leave them in their cages. It’s easy for me because I’m retired so have more time. I guess it’s about maximising floor time in accordance with your commitments giving them as much exercise as possible
My 3 piggies roam freely in the living room, where their hutch with an attached c&c cage at the bottom is. They are out the cage from 8am to 10pm and are locked during bedtime at night, or when hubby and I have to be out for the day.
My boars have a large enclosure inside so plenty of space to run around. They do get floor time when I clean out their home but they don't really move, strange boys! I put the clean fleece on the floor outside their enclosure and put all their hideys etc on it too but they hardly move. They are so excited when they move back in to their nice cleaned out space ( with some old hay so they know where they are) and instantly start exploring and more often than not popcorning and zooming follows
Mine always get 2-3 hours of floor time twice a week on cage clean days, in bunny business play pens with newspaper over a plastic mat on the floor. Its more enrichment and a change of scenery than exercise, I spend quite a while setting things up nicely for them with scattered hay piles and veggies, paper bags with hay and treat veg, cardboard box houses, and the seagrass and cardboard tube hideys that they only get in the playpen because they wouldnt last long in the cage!