I've had a couple of periods where I was flat broke and had food staples and a roof over my head but not much else in Canadian winter or two. That's essentially how I would pass a few days here and there to save money on food and expenses.
I would sleep as much as possible, fast until around 8pm, and eat a cheap meal (e.g. bulk pasta and tomato sauce I made from marked down cans of tomato and froze), then back to bed. A lot of the time, if I couldn't sleep, I would read. This was pre internet and I didn't have a phone or tv.
Days go by pretty fast like that (it was very, very cold out each time I did this and I had inadequate clothing for the weather so even a walk was not happening).
Eventually, the next thing I had to do would come up and I'd get back to normal. For context, I worked in kitchens so work meant "free" food (my jobs paid very little) or a couple times I was in a cabin in the middle of nowhere waiting for the weather to clear so I could dig out and get my car in the road. Nice to do this when you have a good supply of stove wood and a good book.