Yikes, who told you dogs have no sense of time? If anything, dogs have an amazingly acute sense of time. Dogs love schedules and easily adjust their internal "clocks" to your schedule. They then begin to anticipate your arrival, your departures, dinner, breakfast, the evening walk, etc. Heck, they have a better sense of time than I do

IMO, it is not in a young dog or active dog's best interest to be left alone for the whole day. However, you can adopt an older, less active dog who can tolerate 7-8 hours alone. I must say, though, 8 hours would be my limit to how long a dog is alone. That's a long time to hold your bladder! Your beagle probably just trashed your place because he was bored. You know, retired racing greyhounds are called 45 mph couch potatoes for a reason