If you share a bedroom and sleep approximately the same hours then I think that counts as "time together". So that's like 50 hours per week before you have a chat or go jogging together. Just saying.
Time spent with another person doesn't have to be face to face chatting (or even jogging together or going out for meals).
I haven't lived with a partner in a few years, but when I last did, we were both unemployed and spent pretty much all day together. If you subtracted toilet breaks, and occasional walks into different rooms of the house to find a TV remote control or whatever, and then rounded down the hours we spent together, then we probably came out at 23 hours per day. Maybe once in a while it was 22 hours if she went to see her therapist that day. Obviously it wasn't an ideal relationship, nor was either of us living an ideal life.
Some people go the whole hog on "independence" or "solitude" and even sleep in a separate room to their partner. (even though they live in the same house). I even met one guy whose wife lived in a different city (they didn't have any children).
Some people think that every human should form a pairbond to have the most fulfilling life, but then again some people take a vow of celibacy and go live in an ashram/temple/monastery. If you do form a pairbond then I suppose every relationship is unique, and different couples have different ideas of what is "too much time together" or "too much time apart".
I haven't been in a realtionship in a few years, but I imagine the next time I live with a girl, we'd probably want at least 8 hours per week on top of the ~50 sleeping hours together. With that said though, I'm a very different person today than I was a few years ago.