Good question! The answer: There’s no time like the present. Sort of.
For the most part, dogs live blissfully in the moment. They’re unable to store long-term memories or perceive time in relation to past events and can’t use reasoning to anticipate future events. In fact, some studies show that a dog can’t make a connection between a behavior and a consequence if more than four seconds pass between the two.
However, dogs can comprehend the passing of time in relation to their own internal clock. They depend on circadian oscillators – daily fluctuations of hormones, body temperature and neural activity – to tell how much time has passed during the day. Instead of knowing what time you come home from work or when you usually put food in their bowl, dogs react to the biological state they reach at that particular time of day.
This is why your pup has that uncanny knack of watching out the front window for you right as you pull into the driveway, and why he begs for food right around dinnertime.
It also means that yes, your dog does know the difference if you’ve been gone for an hour or for eight hours, even though they can’t recall the exact moment you left and can’t anticipate your return.
That is, until their body tells them it’s time.