The 3:45 Room
The 3:45 Room exists in an otherwise unremarkable office building, in an appropriately convenient city. The Room is 15’ by 15’ by 10’; it contains a cot, toilet, shower head, hot plate, ceiling light, microwave, combination desk and mini-fridge, wall cabinet, stopped clock set to 3:45, and no electrical outlets whatsoever (the appliances are all spliced directly into the wall). Cell phones and wifi inexplicably fail to work inside the Room; supernatural attempts to scry its interior, or communicate from inside the Room, do not end well. All of this is helpfully explained on a sign on the door leading to the 3:45 Room.
Using the 3:45 Room is very straightforward: if you enter the Room prior to 3:45 AM, close the door, and stay in the Room past what would normally be 3:45 AM on a particular day, when you finally open the door the time will still be at precisely 3:45 AM on the dot, and that same day. The most that anybody’s spent in the Room, subjectively speaking, has been about 2 weeks; the most that anybody’s been able to stuff into the Room at one time has been about eighty people, and they didn’t enjoy it much. Attempts to open the door to the Room from the outside at 3:45 AM on the dot have yet to succeed. Human beings simply don’t have the reflexes needed, and computers apparently aren’t much better.
The 3:45 Room technically has a three-month waiting list for open slots. The waiting list is wholly artificial: the controllers of the Room could easily keep it booked in advance for years. Instead, there is a convoluted and not wholly understood method by which a new slot is auctioned off, or granted, or won every night. Positions on the waiting list can be freely traded, and someone with an existing slot is allowed to bring in extra people, which effectively means that sufficient amounts of money can still get access to the Room on relatively short notice. It all depends on how much someone is willing to pay to get an extra hour, or day, or week of time before a deadline. Very often, that can be quite a lot.
Finally: it is possible to die in the Room. It’s just apparently not possible to die in the Room in a way that doesn’t somehow coincidentally open the door. This is not something that has been extensively tested, though: the people who currently control access to the 3:45 Room in fact have a functional moral sense.