RE: dogs and cats...
Appartment cats tend to sleep most of the day when you are out. And they are primarily naucturnal. They get active at night. I think it's instinct. I don't think they really understand a concept of time.
Dogs can't really tell time, but they are easily conditioned to your schedule and habits. Specially if you are the Alpha. Dogs take naps and occasionally go into a deep REM sleep. That's when they twitch and make funny sounds while they are sleeping. But they don't usually do this for more than twenty or thirty minutes.
Dogs can anticipate you're departure and arrival. That's your fault. You condition them, they don't actually tell time. They pick up on your body language and the sounds you make when you decide to do something...like getting food, going outside, getting up in the morning, going to bed at night, etc, etc...
I used to have a dog that wore a wrist watch. He could tell time. He would wake me up in the morning for work and keep my appointments in order for me. And he was never, ever late for dinner. I'll miss him.
On the other hand I used to have a cat, and I never bought her a watch. She was disorganized, late for meals, kept funny hours, slept all day and was up all night. I could never depend on her to wake me up for work on time and my life was chaotic and disorganized just like hers. She was trouble, but I loved her.
Later,
bobsled.