To give you a straight answer regarding the 7 hours: for an adult dog, that's a standard amount of time and perfectly doable, as long as bladder control and boredom are sorted. For a puppy, the issue isn't primarily emotional, it's physiological – a common rule of thumb for how long they can hold their bladder is "age in months + 1": so 2 months old = roughly 3 hours, 4 months = 5 hours. Anything longer than that isn't a training issue; they simply can't hold it in.
So, the real question is how old your dog is – you mention a puppy and then a dog, and the advice differs for each. If he's an adult, your morning and evening routine already covers the essentials.
The best way to stop guessing is to use an old phone to film him for 20 minutes after you leave. Most dogs will pace around a bit and then settle down within a quarter of an hour – and seeing that for yourself is worth more than any advice on a forum. If, on the other hand, he’s still standing there panting, scratching at the door, or vocalising after 20 minutes, then you've got something to work on.
One last point, which is often the most helpful: it’s not so much the number of hours that matters, but how you leave and how you come back. Low-key departures and returns – no drawn-out goodbyes and no making a big fuss for the first few minutes – do more to keep a dog calm than any other trick.
And the very fact that you’re even asking the question is a good sign.
