Make a huge bounce in history
Do time travel to speak with historical figures? Damn, that's the dream of any historian or newspaper. Imagine how valuable an interview with Cesar, Jesus or Ghengis Khan would be. You could also know the exact location of cities, artifacts and such. You would be able to study what daily life was like as you could never hope to before.
Infinite amount of time
When you come back out it's almost as if no time has passed at all, so your body is pretty much untouched.
This is also very valuable. If anyone (or a whole group) needs time to think about something, meditate, or do anything else that takes time, they can do it this way. Some conflicts are hard to resolve, but with an infinite amount of time? I'm not saying it would solve everything, but time is one of the limitation of negotiations.
You are burned out and need some vacation? HistoryTravel is here for you! For a few thousands dollars, we offer you a long trip during whatever time period you want. Do you prefer a gladiator combat, or being a crusader knight? With HistoryTravel, you can do whatever you want!
Seriously, travel in time would make really good holidays. Sure, only the rich people could afford it, but there is a huge market. Bonus point: you can do it during your lunch time.
Another advantage of having more or less infinite amount of time: You could study whatever you want. Either bring a teacher and a class, and you could learn, for example, a new language. Even if it takes several years in the pocket universe, from perspective of the current world, you enter the machine during the morning and come out the same day knowing how to speak German.
Even better, you're travel in time, so you could go to university and study with historical figures, such as Einstein.
Want to know what happen if WW3 happened today? Want to know what would happen if you ask your crush out? Want to do some crazy dreams that costs all your money? Well, you can. Just enter your pocket universe close to today's date, trigger what you want and grab some popcorn. Basically, if you can travel to yesterday and then stay in your pocket universe for ten years, you can do a forward travel. Don't forget to bring back some ideas for new technologies.
You could also experience near past things such as in abigail's answer.